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Oriol Vinyals: DeepMind AlphaStar, StarCraft, Language, and Sequences

第2019-04-29期2019-04-29English

嘉宾:Oriol Vinyals

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§01Transcript · 00:00–08:53

00:00The following is a conversation with Ariel Vinales.

00:03He's a senior research scientist at Google DeepMind,

00:05and before that, he was at Google Brain and Berkeley.

00:09His research has been cited over 39,000 times.

00:13He's truly one of the most brilliant and impactful minds

00:16in the field of deep learning.

00:18He's behind some of the biggest papers and ideas in AI,

00:20including sequence to sequence learning,

00:23audio generation, image captioning,

00:25neural machine translation,

00:27and, of course, reinforcement learning.

00:29He's a lead researcher of the AlphaStar project,

00:32creating an agent that defeated a top professional

00:35at the game of StarCraft.

00:38This conversation is part

00:39of the Artificial Intelligence podcast.

00:41If you enjoy it, subscribe on YouTube, iTunes,

00:44or simply connect with me on Twitter at Lex Friedman,

00:48spelled F R I D.

00:51And now, here's my conversation with Ariel Vinales.

00:55You spearheaded the DeepMind team behind AlphaStar

00:59that recently beat a top professional player at StarCraft.

01:04So you have an incredible wealth of work

01:07in deep learning and a bunch of fields,

01:09but let's talk about StarCraft first.

01:11Let's go back to the very beginning,

01:13even before AlphaStar, before DeepMind,

01:16before deep learning first.

01:18What came first for you,

01:21a love for programming or a love for video games?

01:24I think for me, it definitely came first

01:28the drive to play video games.

01:31I really liked computers.

01:35I didn't really code much, but what I would do is

01:38I would just mess with the computer, break it and fix it.

01:42That was the level of skills, I guess,

01:43that I gained in my very early days,

01:46I mean, when I was 10 or 11.

01:48And then I really got into video games,

01:50especially StarCraft, actually, the first version.

01:53I spent most of my time

01:55just playing kind of pseudo professionally,

01:57as professionally as you could play back in 98 in Europe,

02:01which was not a very main scene

02:03like what's called nowadays eSports.

02:05Right, of course, in the 90s.

02:07So how'd you get into StarCraft?

02:09What was your favorite race?

02:11How did you develop your skill?

02:15What was your strategy?

02:16All that kind of thing.

02:18So as a player, I tended to try to play not many games,

02:21not to kind of disclose the strategies

02:23that I kind of developed.

02:25And I like to play random, actually,

02:27not in competitions, but just to...

02:30I think in StarCraft, there's three main races

02:33and I found it very useful to play with all of them.

02:36And so I would choose random many times,

02:38even sometimes in tournaments,

02:40to gain skill on the three races

02:42because it's not how you play against someone,

02:45but also if you understand the race because you played,

02:48you also understand what's annoying,

02:51then when you're on the other side,

02:52what to do to annoy that person,

02:54to try to gain advantages here and there and so on.

02:57So I actually played random,

02:59although I must say in terms of favorite race,

03:02I really liked Zerg.

03:03I was probably best at Zerg

03:05and that's probably what I tend to use

03:08towards the end of my career before starting university.

03:11So let's step back a little bit.

03:13Could you try to describe StarCraft

03:15to people that may never have played video games,

03:18especially the massively online variety like StarCraft?

03:22So StarCraft is a real time strategy game.

03:25And the way to think about StarCraft,

03:27perhaps if you understand a bit chess,

03:30is that there's a board which is called map

03:34or the map where people play against each other.

03:39There's obviously many ways you can play,

03:40but the most interesting one is the one versus one setup

03:44where you just play against someone else

03:47or even the built in AI, right?

03:49Blizzard put a system that can play the game

03:51reasonably well if you don't know how to play.

03:54And then in this board, you have again,

03:57pieces like in chess,

03:58but these pieces are not there initially

04:01like they are in chess.

04:02You actually need to decide to gather resources

04:05to decide which pieces to build.

04:07So in a way you're starting almost with no pieces.

04:10You start gathering resources in StarCraft.

04:13There's minerals and gas that you can gather.

04:16And then you must decide how much do you wanna focus

04:19for instance, on gathering more resources

04:21or starting to build units or pieces.

04:24And then once you have enough pieces

04:27or maybe like attack, a good attack composition,

04:32then you go and attack the other side of the map.

04:35And now the other main difference with chess

04:37is that you don't see the other side of the map.

04:39So you're not seeing the moves of the enemy.

04:43It's what we call partially observable.

04:45So as a result, you must not only decide

04:48trading off economy versus building your own units,

04:52but you also must decide whether you wanna scout

04:54to gather information, but also by scouting,

04:57you might be giving away some information

04:59that you might be hiding from the enemy.

05:01So there's a lot of complex decision making

05:04all in real time.

05:06There's also unlike chess, this is not a turn based game.

05:10You play basically all the time continuously

05:13and thus some skill in terms of speed

05:16and accuracy of clicking is also very important.

05:18And people that train for this really play this game

05:21at an amazing skill level.

05:23I've seen many times these

05:25and if you can witness this life,

05:27it's really, really impressive.

05:29So in a way, it's kind of a chess

05:31where you don't see the other side of the board,

05:33you're building your own pieces

05:35and you also need to gather resources

05:37to basically get some money to build other buildings,

05:40pieces, technology and so on.

05:42From the perspective of a human player,

05:45the difference between that and chess

05:47or maybe that and a game like turn based strategy

05:50like Heroes of Might and Magic is that there's an anxiety

05:55because you have to make these decisions really quickly.

05:58And if you are not actually aware of what decisions work,

06:04it's a very stressful balance.

06:06Everything you describe is actually quite stressful,

06:08difficult to balance for an amateur human player.

06:11I don't know if it gets easier at the professional level,

06:14like if they're fully aware of what they have to do,

06:16but at the amateur level, there's this anxiety.

06:19Oh crap, I'm being attacked.

06:20Oh crap, I have to build up resource.

06:22Oh, I have to probably expand.

06:24And all these, the time,

06:26the real time strategy aspect is really stressful

06:29and computationally I'm sure difficult.

06:31We'll get into it.

06:32But for me, Battle.net,

06:35so StarCraft was released in 98, 20 years ago,

06:42which is hard to believe.

06:44And Blizzard Battle.net with Diablo in 96 came out.

06:50And to me, it might be a narrow perspective,

06:52but it changed online gaming and perhaps society forever.

06:56Yeah.

06:57But I may have made way too narrow viewpoint,

07:00but from your perspective,

07:02can you talk about the history of gaming

07:05over the past 20 years?

07:06Is this, how transformational,

07:09how important is this line of games?

07:12Right, so I think I kind of was an active gamer

07:16whilst this was developing, the internet, online gaming.

07:20So for me, the way it came was I played other games,

07:24strategy related, I played a bit of Common and Conquer,

07:27and then I played Warcraft II, which is from Blizzard.

07:31But at the time, I didn't know,

07:32I didn't understand about what Blizzard was or anything.

07:35Warcraft II was just a game,

07:36which was actually very similar to StarCraft in many ways.

07:39It's also real time strategy game

07:41where there's orcs and humans, so there's only two races.

07:44But it was offline.

07:46And it was offline, right?

07:47So I remember a friend of mine came to school,

07:51say, oh, there's this new cool game called StarCraft.

07:53And I just said, oh, this sounds like

07:54just a copy of Warcraft II, until I kind of installed it.

07:59And at the time, I am from Spain,

08:01so we didn't have very good internet, right?

08:04So there was, for us,

08:05StarCraft became first kind of an offline experience

08:09where you kind of start to play these missions, right?

08:12You play against some sort of scripted things

08:15to develop the story of the characters in the game.

08:18And then later on, I start playing against the built in AI,

08:23and I thought it was impossible to defeat it.

08:25Then eventually you defeat one

08:27and you can actually play against seven built in AIs

08:29at the same time, which also felt impossible.

08:32But actually, it's not that hard to beat

08:34seven built in AIs at once.

08:36So once we achieved that, also we discovered that

08:40we could play, as I said, internet wasn't that great,

08:43but we could play with the LAN, right?

08:45Like basically against each other

08:47if we were in the same place

08:49because you could just connect machines with like cables,

08:51right?

§02Transcript · 08:53–17:38

08:53So we started playing in LAN mode

08:55and as a group of friends,

08:58and it was really, really like much more entertaining

09:00than playing against AIs.

09:02And later on, as internet was starting to develop

09:05and being a bit faster and more reliable,

09:07then it's when I started experiencing Battle.net,

09:09which is this amazing universe,

09:11not only because of the fact

09:13that you can play the game against anyone in the world,

09:16but you can also get to know more people.

09:20You just get exposed to now like this vast variety of,

09:23it's kind of a bit when the chats came about, right?

09:25There was a chat system.

09:27You could play against people,

09:29but you could also chat with people,

09:30not only about Stalker, but about anything.

09:32And that became a way of life for kind of two years.

09:36And obviously then it became like kind of,

09:38it exploded in me in that I started to play more seriously,

09:42going to tournaments and so on and so forth.

09:44Do you have a sense on a societal, sociological level,

09:49what's this whole part of society

09:52that many of us are not aware of

09:53and it's a huge part of society, which is gamers.

09:56I mean, every time I come across that in YouTube

10:00or streaming sites, I mean,

10:03this is the huge number of people play games religiously.

10:07Do you have a sense of those folks,

10:08especially now that you've returned to that realm

10:10a little bit on the AI side?

10:12Yeah, so in fact, even after Stalker,

10:15I actually played World of Warcraft,

10:17which is maybe the main sort of online worlds

10:21or in presence that you get to interact

10:23with lots of people.

10:24So I played that for a little bit.

10:26It was to me, it was a bit less stressful than StarCraft

10:29because winning was kind of a given.

10:30You just put in this world

10:32and you can always complete missions.

10:34But I think it was actually the social aspect

10:38of especially StarCraft first

10:40and then games like World of Warcraft

10:43really shaped me in a very interesting ways

10:46because what you get to experience

10:48is just people you wouldn't usually interact with, right?

10:51So even nowadays, I still have many Facebook friends

10:54from the area where I played online

10:56and their ways of thinking is even political.

11:00They just, we don't live in,

11:01like we don't interact in the real world,

11:03but we were connected by basically fiber.

11:06And that way I actually get to understand a bit better

11:10that we live in a diverse world.

11:12And these were just connections that were made by,

11:15because, you know, I happened to go in a city

11:18in a virtual city as a priest and I met this warrior

11:22and we became friends

11:23and then we start like playing together, right?

11:25So I think it's transformative

11:28and more and more and more people are more aware of it.

11:31I mean, it's becoming quite mainstream,

11:33but back in the day, as you were saying in 2000, 2005,

11:37even it was very, still very strange thing to do,

11:42especially in Europe.

11:44I think there were exceptions like Korea, for instance,

11:47it was amazing that everything happened so early

11:50in terms of cybercafes, like if you go to Seoul,

11:54it's a city that back in the day,

11:57StarCraft was kind of,

11:58you could be a celebrity by playing StarCraft,

12:00but this was like 99, 2000, right?

12:03It's not like recently.

12:04So yeah, it's quite interesting to look back

12:08and yeah, I think it's changing society.

12:10The same way, of course, like technology

12:13and social networks and so on are also transforming things.

12:16And a quick tangent, let me ask,

12:18you're also one of the most productive people

12:20in your particular chosen passion and path in life.

12:26And yet you're also appreciate and enjoy video games.

12:29Do you think it's possible to do,

12:32to enjoy video games in moderation?

12:35Someone told me that you could choose two out of three.

12:39When I was playing video games,

12:41you could choose having a girlfriend,

12:43playing video games or studying.

12:46And I think for the most part, it was relatively true.

12:50These things do take time.

12:52Games like StarCraft,

12:53if you take the game pretty seriously

12:55and you wanna study it,

12:56then you obviously will dedicate more time to it.

12:59And I definitely took gaming

13:01and obviously studying very seriously.

13:03I love learning science and et cetera.

13:08So to me, especially when I started university undergrad,

13:13I kind of step off StarCraft.

13:14I actually fully stopped playing.

13:16And then World of Warcraft was a bit more casual.

13:19You could just connect online.

13:20And I mean, it was fun.

13:22But as I said, that was not as much time investment

13:26as it was for me in StarCraft.

13:29Okay, so let's get into AlphaStar.

13:31What are the, you're behind the team.

13:35So DeepMind has been working on StarCraft

13:37and released a bunch of cool open source agents

13:39and so on the past few years.

13:41But AlphaStar really is the moment

13:43where the first time you beat a world class player.

13:49So what are the parameters of the challenge

13:51in the way that AlphaStar took it on

13:53and how did you and David

13:55and the rest of the DeepMind team get into it?

13:58Consider that you can even beat the best in the world

14:00or top players.

14:02I think it all started back in 2015.

14:08Actually, I'm lying.

14:08I think it was 2014 when DeepMind was acquired by Google.

14:14And I at the time was at Google Brain,

14:15which was in California, is still in California.

14:18We had this summit where we got together, the two groups.

14:21So Google Brain and Google DeepMind got together

14:24and we gave a series of talks.

14:26And given that they were doing

14:28deep reinforcement learning for games,

14:30I decided to bring up part of my past,

14:33which I had developed at Berkeley,

14:35like this thing which we call Berkeley OverMind,

14:37which is really just a StarCraft one bot, right?

14:40So I talked about that.

14:42And I remember Demis just came to me and said,

14:44well, maybe not now, it's perhaps a bit too early,

14:47but you should just come to DeepMind

14:48and do this again with deep reinforcement learning, right?

14:53And at the time it sounded very science fiction

14:56for several reasons.

14:58But then in 2016, when I actually moved to London

15:01and joined DeepMind transferring from Brain,

15:04it became apparent that because of the AlphaGo moment

15:08and kind of Blizzard reaching out to us to say,

15:11wait, like, do you want the next challenge?

15:13And also me being full time at DeepMind,

15:15so sort of kind of all these came together.

15:17And then I went to Irvine in California,

15:20to the Blizzard headquarters to just chat with them

15:23and try to explain how would it all work

15:26before you do anything.

15:27And the approach has always been

15:30about the learning perspective, right?

15:33So in Berkeley, we did a lot of rule based conditioning

15:39and if you have more than three units, then go attack.

15:42And if the other has more units than me,

15:44I retreat and so on and so forth.

15:46And of course, the point of deep reinforcement learning,

15:48deep learning, machine learning in general

15:50is that all these should be learned behavior.

15:53So that kind of was the DNA of the project

15:56since its inception in 2016,

15:59where we just didn't even have an environment to work with.

16:02And so that's how it all started really.

16:05So if you go back to that conversation with Demis

16:08or even in your own head, how far away did you,

16:12because we're talking about Atari games,

16:14we're talking about Go, which is kind of,

16:16if you're honest about it, really far away from StarCraft.

16:20In, well, now that you've beaten it,

16:22maybe you could say it's close,

16:23but it's much, it seems like StarCraft

16:25is way harder than Go philosophically

16:29and mathematically speaking.

16:30So how far away did you think you were?

16:34Do you think it's 2019 and 18

16:36you could be doing as well as you have?

16:37Yeah, when I kind of thought about,

16:40okay, I'm gonna dedicate a lot of my time

16:43and focus on this.

16:44And obviously I do a lot of different research

16:47in deep learning.

16:48So spending time on it, I mean,

16:50I really had to kind of think

16:51there's gonna be something good happening out of this.

16:55So really I thought, well, this sounds impossible.

16:58And it probably is impossible to do the full thing,

17:01like the full game where you play one versus one

17:06and it's only a neural network playing and so on.

17:09So it really felt like,

17:10I just didn't even think it was possible.

17:13But on the other hand,

17:14I could see some stepping stones towards that goal.

17:18Clearly you could define sub problems in StarCraft

17:21and sort of dissect it a bit and say,

17:22okay, here is a part of the game, here's another part.

17:26And also obviously the fact,

17:29so this was really also critical to me,

17:31the fact that we could access human replays, right?

17:34So Blizzard was very kind.

17:35And in fact, they open source these for the whole community

§03Transcript · 17:38–26:12

17:38where you can just go

17:39and it's not every single StarCraft game ever played,

17:42but it's a lot of them you can just go and download.

17:45And every day they will,

17:47you can just query a data set and say,

17:48well, give me all the games that were played today.

17:51And given my kind of experience with language

17:55and sequences and supervised learning,

17:57I thought, well, that's definitely gonna be very helpful

18:00and something quite unique now,

18:02because ever before we had such a large data set of replays,

18:08of people playing the game at this scale

18:10of such a complex video game, right?

18:12So that to me was a precious resource.

18:15And as soon as I knew that Blizzard

18:17was able to kind of give this to the community,

18:20I started to feel positive

18:22about something non trivial happening.

18:24But I also thought the full thing, like really no rules,

18:28no single line of code that tries to say,

18:31well, I mean, if you see this unit, build a detector,

18:33all these, not having any of these specializations

18:36seemed really, really, really difficult to me.

18:38Intuitively.

18:39I do also like that Blizzard was teasing

18:42or even trolling you,

18:45sort of almost, yeah, pulling you in

18:48into this really difficult challenge.

18:50Do they have any awareness?

18:51What's the interest from the perspective of Blizzard,

18:55except just curiosity?

18:57Yeah, I think Blizzard has really understood

18:59and really bring forward this competitiveness

19:03of esports in games.

19:04The StarCraft really kind of sparked a lot of,

19:07like something that almost was never seen,

19:10especially as I was saying, back in Korea.

19:13So they just probably thought,

19:16well, this is such a pure one versus one setup

19:18that it would be great to see

19:21if something that can play Atari or Go

19:24and then later on chess could even tackle

19:27these kind of complex real time strategy game, right?

19:30So for them, they wanted to see first,

19:33obviously whether it was possible,

19:36if the game they created was in a way solvable

19:39to some extent.

19:40And I think on the other hand,

19:42they also are a pretty modern company that innovates a lot.

19:45So just starting to understand AI for them

19:48to how to bring AI into games

19:50is not AI for games, but games for AI, right?

19:54I mean, both ways I think can work.

19:56And we obviously at DeepMind use games for AI, right?

20:00To drive AI progress,

20:01but Blizzard might actually be able to do

20:03and many other companies to start to understand

20:06and do the opposite.

20:06So I think that is also something

20:08they can get out of these.

20:09And they definitely, we have brainstormed a lot

20:12about these, right?

20:13But one of the interesting things to me

20:15about StarCraft and Diablo

20:17and these games that Blizzard has created

20:19is the task of balancing classes, for example.

20:23Sort of making the game fair from the starting point

20:27and then let skill determine the outcome.

20:30Is there, I mean, can you first comment,

20:33there's three races, Zerg, Protoss and Terran.

20:36I don't know if I've ever said that out loud.

20:38Is that how you pronounce it?

20:40Terran?

20:40Yeah, Terran.

20:41Yeah.

20:44Yeah, I don't think I've ever in person interacted

20:46with anybody about StarCraft, that's funny.

20:49So they seem to be pretty balanced.

20:51I wonder if the AI, the work that you're doing

20:56with AlphaStar would help balance them even further.

20:59Is that something you think about?

21:00Is that something that Blizzard is thinking about?

21:03Right, so balancing when you add a new unit

21:06or a new spell type is obviously possible

21:09given that you can always train or pre train at scale

21:13some agent that might start using that in unintended ways.

21:16But I think actually, if you understand

21:19how StarCraft has kind of co evolved with players,

21:22in a way, I think it's actually very cool

21:24the ways that many of the things and strategies

21:27that people came up with, right?

21:28So I think we've seen it over and over in StarCraft

21:32that Blizzard comes up with maybe a new unit

21:35and then some players get creative

21:37and do something kind of unintentional

21:39or something that Blizzard designers

21:40that just simply didn't test or think about.

21:43And then after that becomes kind of mainstream

21:46in the community, Blizzard patches the game

21:48and then they kind of maybe weaken that strategy

21:51or make it actually more interesting

21:53but a bit more balanced.

21:55So these kind of continual talk between players

21:57and Blizzard is kind of what has defined them actually

22:01in actually most games in StarCraft

22:04but also in World of Warcraft, they would do that.

22:06There are several classes and it would be not good

22:09that everyone plays absolutely the same race and so on, right?

22:13So I think they do care about balancing of course

22:17and they do a fair amount of testing

22:19but it's also beautiful to also see

22:22how players get creative anyways.

22:24And I mean, whether AI can be more creative at this point,

22:27I don't think so, right?

22:28I mean, it's just sometimes something so amazing happens.

22:31Like I remember back in the days,

22:33like you have these drop ships that could drop the rivers

22:36and that was actually not thought about

22:39that you could drop this unit

22:41that has this what's called splash damage

22:43that would basically eliminate

22:45all the enemies workers at once.

22:47No one thought that you could actually put them

22:50in really early game, do that kind of damage

22:53and then things change in the game.

22:55But I don't know, I think it's quite an amazing

22:58exploration process from both sides,

23:00players and Blizzard alike.

23:01Well, it's almost like a reinforcement learning exploration

23:05but the scale of humans that play Blizzard games

23:11is almost on the scale of a large scale

23:13deep mind RL experiment.

23:15I mean, if you look at the numbers,

23:17I mean, you're talking about, I don't know how many games

23:19but hundreds of thousands of games probably a month.

23:22Yeah.

23:22I mean, so it's almost the same as running RL agents.

23:28What aspect of the problem of Starcraft

23:31do you think is the hardest?

23:32Is it the, like you said, the imperfect information?

23:35Is it the fact they have to do longterm planning?

23:38Is it the real time aspects?

23:40We have to do stuff really quickly.

23:42Is it the fact that a large action space

23:44so you can do so many possible things?

23:47Or is it, you know, in the game theoretic sense

23:51there is no Nash equilibrium

23:52or at least you don't know what the optimal strategy is

23:54because there's way too many options.

23:56Right.

23:57Is there something that stands out as just like the hardest

23:59the most annoying thing?

24:01So when we sort of looked at the problem

24:04and start to define like the parameters of it, right?

24:07What are the observations?

24:08What are the actions?

24:10It became very apparent that, you know,

24:13the very first barrier that one would hit in Starcraft

24:17would be because of the action space being so large

24:20and as not being able to search like you could in chess

24:24or go even though the search space is vast.

24:28The main problem that we identified

24:30was that of exploration, right?

24:32So without any sort of human knowledge or human prior,

24:36if you think about Starcraft

24:38and you know how deep reinforcement learnings algorithm

24:40work which is essentially by issuing random actions

24:45and hoping that they will get some wins sometimes

24:47so they could learn.

24:49So if you think of the action space in Starcraft

24:52almost anything you can do in the early game is bad

24:55because any action involves taking workers

24:58which are mining minerals for free.

25:01That's something that the game does automatically

25:03sends them to mine.

25:04And you would immediately just take them out of mining

25:07and send them around.

25:09So just thinking how is it gonna be possible

25:13to get to understand these concepts

25:16but even more like expanding, right?

25:19There's these buildings you can place

25:21in other locations in the map to gather more resources

25:24but the location of the building is important

25:26and you have to select a worker,

25:28send it walking to that location, build the building,

25:32wait for the building to be built

25:34and then put extra workers there so they start mining.

25:37That feels like impossible if you just randomly click

25:41to produce that state, desirable state

25:44that then you could hope to learn from

25:46because eventually that may yield to an extra win, right?

25:49So for me, the exploration problem

25:51and due to the action space

25:53and the fact that there's not really turns,

25:56there's so many turns because the game essentially

25:59takes that 22 times per second.

26:02I mean, that's how they could discretize sort of time.

26:05Obviously you always have to discretize time

26:07but there's no such thing as real time

26:09but it's really a lot of time steps

§04Transcript · 26:12–34:53

26:12of things that could go wrong.

26:14And that definitely felt a priori like the hardest.

26:17You mentioned many good ones.

26:19I think partial observability

26:21and the fact that there is no perfect strategy

26:23because of the partial observability.

26:25Those are very interesting problems.

26:26We start seeing more and more now

26:28in terms of as we solve the previous ones

26:31but the core problem to me was exploration

26:34and solving it has been basically kind of the focus

26:37and how we saw the first breakthroughs.

26:39So exploration in a multi hierarchical way.

26:43So like 22 times a second exploration

26:46has a very different meaning than it does

26:48in terms of should I gather resources early

26:51or should I wait or so on.

26:53So how do you solve the longterm?

26:56Let's talk about the internals of AlphaStar.

26:58So first of all, how do you represent the state

27:02of the game as an input?

27:05How do you then do the longterm sequence modeling?

27:08How do you build a policy?

27:10What's the architecture like?

27:12So AlphaStar has obviously several components

27:16but everything passes through what we call the policy

27:20which is a neural network.

27:22And that's kind of the beauty of it.

27:24There is, I could just now give you a neural network

27:27and some weights.

27:28And if you fed the right observations

27:30and you understood the actions the same way we do

27:32you would have basically the agent playing the game.

27:35There's absolutely nothing else needed

27:37other than those weights that were trained.

27:40Now, the first step is observing the game

27:43and we've experimented with a few alternatives.

27:46The one that we currently use mixes both spatial

27:50sort of images that you would process from the game

27:53that is the zoomed out version of the map

27:56and also a zoomed in version of the camera

27:58or the screen as we call it.

28:00But also we give to the agent the list of units

28:04that it sees more of as a set of objects

28:09that it can operate on.

28:11That is not necessarily required to use it.

28:14And we have versions of the game that play well

28:16without this set vision that is a bit not like

28:19how humans perceive the game.

28:21But it certainly helps a lot

28:23because it's a very natural way to encode the game

28:26is by just looking at all the units that there are.

28:29They have properties like health, position, type of unit

28:33whether it's my unit or the enemies.

28:36And that sort of is kind of the summary

28:40of the state of the game,

28:43that list of units or set of units

28:45that you see all the time.

28:47But that's pretty close to the way humans see the game.

28:49Why do you say it's not, isn't that,

28:51you're saying the exactness of it is not similar to humans?

28:55The exactness of it is perhaps not the problem.

28:57I guess maybe the problem if you look at it

28:59from how actually humans play the game

29:02is that they play with a mouse and a keyboard and a screen

29:05and they don't see sort of a structured object

29:08with all the units.

29:09What they see is what they see on the screen, right?

29:12So.

29:13Remember that there's a, sorry to interrupt,

29:14there's a plot that you showed with camera base

29:16where you do exactly that, right?

29:18You move around and that seems to converge

29:21to similar performance.

29:22Yeah, I think that's what I,

29:23we're kind of experimenting with what's necessary or not,

29:26but using the set.

29:28So, actually, if you look at research in computer vision,

29:32where it makes a lot of sense to treat images

29:35as two dimensional arrays,

29:38there's actually a very nice paper from Facebook.

29:40I think, I forgot who the authors are,

29:42but I think it's part of Caming's group.

29:46And what they do is they take an image,

29:49which is this two dimensional signal,

29:51and they actually take pixel by pixel

29:54and scramble the image as if it was just a list of pixels.

29:59Crucially, they encode the position of the pixels

30:01with the X, Y coordinates.

30:03And this is just kind of a new architecture,

30:06which we incidentally also use in StarCraft

30:08called the Transformer,

30:09which is a very popular paper from last year,

30:11which yielded very nice result in machine translation.

30:15And if you actually believe in this kind of,

30:18oh, it's actually a set of pixels,

30:20as long as you encode X, Y, it's okay,

30:22then you could argue that the list of units that we see

30:26is precisely that,

30:26because we have each unit as a kind of pixel, if you will,

30:31and then their X, Y coordinates.

30:33So in that perspective, we, without knowing it,

30:36we use the same architecture that was shown

30:38to work very well on Pascal and ImageNet and so on.

30:41So the interesting thing here is putting it in that way

30:45it starts to move it towards

30:46the way you usually work with language.

30:49So what, and especially with your expertise

30:52and work in language,

30:55it seems like there's echoes of a lot of

30:58the way you would work with natural language

31:00in the way you've approached AlphaStar.

31:02Right.

31:03What's, does that help

31:05with the longterm sequence modeling there somehow?

31:08Exactly, so now that we understand

31:10what an observation for a given time step is,

31:13we need to move on to say,

31:14well, there's going to be a sequence of such observations

31:17and an agent will need to, given all that it's seen,

31:21not only the current time step, but all that it's seen, why?

31:24Because there is partial observability.

31:25We must remember whether we saw a worker going somewhere,

31:29for instance, right?

31:30Because then there might be an expansion

31:31on the top right of the map.

31:33So given that, what you must then think about is

31:37there is the problem of given all the observations,

31:40you have to predict the next action.

31:42And not only given all the observations,

31:44but given all the observations

31:45and given all the actions you've taken,

31:47predict the next action.

31:49And that sounds exactly like machine translation where,

31:53and that's exactly how kind of I saw the problem,

31:57especially when you are given supervised data

31:59or replays from humans,

32:01because the problem is exactly the same.

32:03You're translating essentially a prefix of observations

32:07and actions onto what's going to happen next,

32:10which is exactly how you would train a model to translate

32:12or to generate language as well, right?

32:14Do you have a certain prefix?

32:16You must remember everything that comes in the past

32:18because otherwise you might start having noncoherent text.

32:22And the same architectures we're using LSTMs

32:26and transformers to operate on across time

32:29to kind of integrate all that's happened in the past.

32:33Those architectures that work so well in translation

32:35or language modeling are exactly the same

32:38than what the agent is using to issue actions in the game.

32:42And the way we train it, moreover, for imitation,

32:44which is step one of AlphaStar is,

32:47take all the human experience and try to imitate it,

32:49much like you try to imitate translators

32:52that translated many pairs of sentences

32:55from French to English say,

32:57that sort of principle applies exactly the same.

33:00It's almost the same code, except that instead of words,

33:04you have a slightly more complicated objects,

33:06which are the observations and the actions

33:08are also a bit more complicated than a word.

33:11Is there a self play component then too?

33:13So once you run out of imitation?

33:16Right, so indeed you can bootstrap from human replays,

33:22but then the agents you get are actually not as good

33:25as the humans you imitated, right?

33:28So how do we imitate?

33:30Well, we take humans from 3000 MMR and higher.

33:343000 MMR is just a metric of human skill

33:37and 3000 MMR might be like 50% percentile, right?

33:41So it's just average human.

33:43What's that?

33:44So maybe quick pause, MMR is a ranking scale,

33:47the matchmaking rating for players.

33:50So it's 3000, I remember there's like a master

33:52and a grand master, what's 3000?

33:54So 3000 is pretty bad.

33:56I think it's kind of goals level.

33:58It just sounds really good relative to chess, I think.

34:00Oh yeah, yeah, no, the ratings,

34:02the best in the world are at 7,000 MMR.

34:05So 3000, it's a bit like Elo indeed, right?

34:07So 3,500 just allows us to not filter a lot of the data.

34:13So we like to have a lot of data in deep learning

34:15as you probably know.

34:17So we take these kind of 3,500 and above,

34:20but then we do a very interesting trick,

34:22which is we tell the neural network

34:25what level they are imitating.

34:27So we say, this replay you're gonna try to imitate

34:30to predict the next action for all the actions

34:33that you're gonna see is a 4,000 MMR replay.

34:36This one is a 6,000 MMR replay.

34:38And what's cool about this is then we take this policy

34:42that is being trained from human,

34:44and then we can ask it to play like a 3000 MMR player

34:47by setting a beat saying, well, okay,

34:49play like a 3000 MMR player

34:51or play like a 6,000 MMR player.

§05Transcript · 34:53–43:41

34:53And you actually see how the policy behaves differently.

34:57It gets worse economy if you play like a goal level player,

35:01it does less actions per minute,

35:03which is the number of clicks or number of actions

35:05that you will issue in a whole minute.

35:07And it's very interesting to see

35:09that it kind of imitates the skill level quite well.

35:12But if we ask it to play like a 6,000 MMR player,

35:15we tested, of course, these policies to see how well they do.

35:18They actually beat all the built in AIs

35:20that Blizzard put in the game,

35:22but they're nowhere near 6,000 MMR players, right?

35:25They might be maybe around goal level, platinum, perhaps.

35:29So there's still a lot of work to be done for the policy

35:32to truly understand what it means to win.

35:35So far, we only asked them, okay, here is the screen.

35:38And that's what's happened on the game until this point.

35:41What would the next action be if we ask a pro to now say,

35:46oh, you're gonna click here or here or there.

35:49And the point is experiencing wins and losses

35:53is very important to then start to refine.

35:56Otherwise the policy can get loose,

35:58can just go off policy as we call it.

36:00That's so interesting that you can at least hope eventually

36:03to be able to control a policy

36:06approximately to be at some MMR level.

36:10That's so interesting, especially given that you have

36:12ground truth for a lot of these cases.

36:15Can I ask you a personal question?

36:17What's your MMR?

36:19Well, I haven't played StarCraft II, so I am unranked,

36:23which is the kind of lowest league.

36:26So I used to play StarCraft, the first one.

36:29But you haven't seriously played StarCraft II.

36:32So the best player we have at DeepMind is about 5,000 MMR,

36:37which is high masters.

36:39It's not at grand master level.

36:42Grand master level will be the top 200 players

36:44in a certain region like Europe or America or Asia.

36:49But for me, it would be hard to say.

36:51I am very bad at the game.

36:53I actually played AlphaStar a bit too late and it beat me.

36:56I remember the whole team was, oh, Oreo, you should play.

36:59And I was, oh, it looks like it's not so good yet.

37:02And then I remember I kind of got busy

37:04and waited an extra week and I played

37:07and it really beat me very badly.

37:09Was that, I mean, how did that feel?

37:11Isn't that an amazing feeling?

37:12That's amazing, yeah.

37:13I mean, obviously I tried my best

37:16and I tried to also impress my,

37:18because I actually played the first game.

37:19So I'm still pretty good at micromanagement.

37:23The problem is I just don't understand StarCraft II.

37:25I understand StarCraft.

37:27And when I played StarCraft,

37:28I probably was consistently like for a couple of years,

37:32top 32 in Europe.

37:34So I was decent, but at the time we didn't have

37:37this kind of MMR system as well established.

37:40So it would be hard to know what it was back then.

37:43So what's the difference in interface

37:44between AlphaStar and StarCraft

37:47and a human player in StarCraft?

37:49Is there any significant differences

37:52between the way they both see the game?

37:54I would say the way they see the game,

37:56there's a few things that are just very hard to simulate.

38:01The main one perhaps, which is obvious in hindsight

38:05is what's called cloaked units, which are invisible units.

38:10So in StarCraft, you can make some units

38:13that you need to have a particular kind of unit

38:16to detect it.

38:18So these units are invisible.

38:20If you cannot detect them, you cannot target them.

38:22So they would just destroy your buildings

38:25or kill your workers.

38:27But despite the fact you cannot target the unit,

38:31there's a shimmer that as a human you observe.

38:34I mean, you need to train a little bit,

38:35you need to pay attention,

38:37but you would see this kind of space time distortion

38:41and you would know, okay, there are, yeah.

38:44Yeah, there's like a wave thing.

38:46Yeah, it's called shimmer.

38:47Space time distortion, I like it.

38:49That's really like, the Blizzard term is shimmer.

38:51Shimmer, okay.

38:52And so these shimmer professional players

38:55actually can see it immediately.

38:57They understand it very well,

38:59but it's still something that requires

39:01certain amount of attention

39:02and it's kind of a bit annoying to deal with.

39:05Whereas for AlphaStar, in terms of vision,

39:08it's very hard for us to simulate sort of,

39:11oh, are you looking at this pixel in the screen and so on?

39:14So the only thing we can do is,

39:17there is a unit that's invisible over there.

39:19So AlphaStar would know that immediately.

39:22Obviously still obeys the rules.

39:24You cannot attack the unit.

39:25You must have a detector and so on,

39:27but it's kind of one of the main things

39:29that it just doesn't feel there's a very proper way.

39:32I mean, you could imagine, oh, you don't have hypers.

39:35Maybe you don't know exactly where it is,

39:37or sometimes you see it, sometimes you don't,

39:39but it's just really, really complicated to get it

39:43so that everyone would agree,

39:44oh, that's the best way to simulate this, right?

39:47It seems like a perception problem.

39:49It is a perception problem.

39:50So the only problem is people, you ask,

39:54oh, what's the difference between

39:55how humans perceive the game?

39:56I would say they wouldn't be able to tell a shimmer

39:59immediately as it appears on the screen,

40:02whereas AlphaStar in principle sees it very sharply, right?

40:05It sees that the bit turned from zero to one,

40:08meaning there's now a unit there,

40:10although you don't know the unit,

40:11or you know that you cannot attack it and so on.

40:15So that from a vision standpoint,

40:18that probably is the one that is kind of the most obvious one.

40:22Then there are things humans cannot do perfectly,

40:25even professionals, which is they might miss a detail,

40:28or they might have not seen a unit.

40:30And obviously as a computer,

40:32if there's a corner of the screen that turns green

40:35because a unit enters the field of view,

40:37that can go into the memory of the agent, the LSTM,

40:41and persist there for a while,

40:42and for however long is relevant, right?

40:45And in terms of action,

40:47it seems like the rate of action from AlphaStar

40:50is comparative, if not slower than professional players,

40:54but it's more precise is what I read.

40:57So that's really probably the one that is causing us

41:01more issues for a couple of reasons, right?

41:05The first one is StarCraft has been an AI environment

41:08for quite a few years.

41:09In fact, I mean, I was participating

41:12in the very first competition back in 2010.

41:15And there's really not been a kind of a very clear set

41:19of rules how the actions per minute,

41:22the rate of actions that you can issue is.

41:24And as a result, these agents or bots that people build

41:29in a kind of almost very cool way,

41:31they do like 20,000, 40,000 actions per minute.

41:35Now, to put this in perspective,

41:37a very good professional human

41:39might do 300 to 800 actions per minute.

41:44They might not be as precise.

41:45That's why the range is a bit tricky to identify exactly.

41:49I mean, 300 actions per minute precisely

41:51is probably realistic.

41:53800 is probably not, but you see humans doing a lot of actions

41:56because they warm up and they kind of select things

41:59and spam and so on just so that when they need,

42:02they have the accuracy.

42:04So we came into this by not having kind of a standard way

42:09to say, well, how do we measure whether an agent is

42:13at human level or not?

42:15On the other hand, we had a huge advantage,

42:18which is because we do imitation learning,

42:21agents turned out to act like humans

42:24in terms of rate of actions, even

42:26precisions and imprecisions of actions

42:28in the supervised policy.

42:30You could see all these.

42:31You could see how agents like to spam click, to move here.

42:34If you played especially Diablo, you wouldn't know what I mean.

42:37I mean, you just like spam, oh, move here, move here,

42:39move here.

42:40You're doing literally like maybe five actions

42:43in two seconds, but these actions are not

42:45very meaningful.

42:46One would have sufficed.

42:48So on the one hand, we start from this imitation policy

42:52that is at the ballpark of the actions per minutes of humans

42:55because it's actually statistically

42:57trying to imitate humans.

42:58So we see these very nicely in the curves

43:01that we showed in the blog post.

43:02There's these actions per minute,

43:04and the distribution looks very human like.

43:07But then, of course, as self play kicks in,

43:10and that's the part we haven't talked too much yet,

43:13but of course, the agent must play against itself to improve,

43:17then there's almost no guarantees

43:19that these actions will not become more precise

43:22or even the rate of actions is going to increase over time.

43:26So what we did, and this is probably

43:29the first attempt that we thought was reasonable,

43:31is we looked at the distribution of actions

43:33for humans for certain windows of time.

43:36And just to give a perspective, because I guess I mentioned

43:39that some of these agents that are programmatic,

§06Transcript · 43:41–52:22

43:41let's call them.

43:42They do 40,000 actions per minute.

43:44Professionals, as I said, do 300 to 800.

43:47So what we looked is we look at the distribution

43:49over professional gamers, and we took reasonably high actions

43:53per minute, but we kind of identify certain cutoffs

43:57after which, even if the agent wanted to act,

44:00these actions would be dropped.

44:02But the problem is this cutoff is probably set a bit too high.

44:07And what ends up happening, even though the games,

44:10and when we ask the professionals and the gamers,

44:12by and large, they feel like it's playing humanlike,

44:15there are some agents that developed maybe slightly

44:20too high APMs, which is actions per minute,

44:24combined with the precision, which

44:27made people start discussing a very interesting issue, which

44:30is, should we have limited these?

44:32Should we just let it lose and see what cool things

44:35it can come up with?

44:37Right?

44:37Interesting.

44:38So this is in itself an extremely interesting

44:41question, but the same way that modeling the shimmer

44:44would be so difficult, modeling absolutely all the details

44:47about muscles and precision and tiredness of humans

44:51would be quite difficult.

44:52So we're really here kind of innovating

44:56in this sense of, OK, what could be maybe

44:58the next iteration of putting more rules that

45:02makes the agents more humanlike in terms of restrictions?

45:06Yeah, putting constraints that.

45:08More constraints, yeah.

45:09That's really interesting.

45:10That's really innovative.

45:11So one of the constraints you put on yourself,

45:15or at least focused in, is on the Protoss race,

45:18as far as I understand.

45:19Can you tell me about the different races

45:21and how they, so Protoss, Terran, and Zerg,

45:26how do they compare?

45:27How do they interact?

45:28Why did you choose Protoss?

45:30Yeah, in the dynamics of the game seen

45:34from a strategic perspective.

45:35So Protoss, so in StarCraft there are three races.

45:39Indeed, in the demonstration, we saw only the Protoss race.

45:43So maybe let's start with that one.

45:45Protoss is kind of the most technologically advanced race.

45:49It has units that are expensive but powerful.

45:53So in general, you want to kind of conserve your units

45:57as you go attack.

45:59And then you want to utilize these tactical advantages

46:03of very fancy spells and so on and so forth.

46:07And at the same time, they're kind of,

46:11people say they're a bit easier to play perhaps.

46:15But that I actually didn't know.

46:17I mean, I just talked now a lot to the players

46:20that we work with, TLO and Mana, and they said, oh yeah,

46:23Protoss is actually, people think,

46:24is actually one of the easiest races.

46:26So perhaps the easier, that doesn't

46:28mean that it's obviously professional players

46:32excel at the three races.

46:34And there's never a race that dominates

46:37for a very long time anyway.

46:38So if you look at the top, I don't know, 100 in the world,

46:41is there one race that dominates that list?

46:44It would be hard to know because it depends on the regions.

46:46I think it's pretty equal in terms of distribution.

46:50And Blizzard wants it to be equal.

46:53They wouldn't want one race like Protoss

46:56to not be representative in the top place.

46:59So definitely, they tried it to be balanced.

47:03So then maybe the opposite race of Protoss is Zerg.

47:07Zerg is a race where you just kind of expand and take over

47:11as many resources as you can, and they

47:14have a very high capacity to regenerate their units.

47:17So if you have an army, it's not that valuable in terms

47:20of losing the whole army is not a big deal as Zerg

47:23because you can then rebuild it.

47:25And given that you generally accumulate

47:28a huge bank of resources, Zergs typically

47:31play by applying a lot of pressure,

47:34maybe losing their whole army, but then rebuilding it

47:37quickly.

47:37So although, of course, every race, I mean, there's never,

47:42I mean, they're pretty diverse.

47:43I mean, there are some units in Zerg that

47:45are technologically advanced, and they do

47:47some very interesting spells.

47:48And there's some units in Protoss that are less valuable,

47:51and you could lose a lot of them and rebuild them,

47:53and it wouldn't be a big deal.

47:55All right, so maybe I'm missing out.

47:57Maybe I'm going to say some dumb stuff, but summary

48:01of strategy.

48:02So first, there's collection of a lot of resources.

48:05That's one option.

48:06The other one is expanding, so building other bases.

48:11Then the other is obviously building units

48:15and attacking with those units.

48:17And then I don't know what else there is.

48:20Maybe there's the different timing of attacks,

48:24like do I attack early, attack late?

48:26What are the different strategies that emerged

48:28that you've learned about?

48:29I've read that a bunch of people are super happy

48:31that you guys have apparently, that Alpha Star apparently

48:34has discovered that it's really good to,

48:36what is it, saturate?

48:38Oh yeah, the mineral line.

48:39Yeah, the mineral line.

48:41Yeah, yeah.

48:42And that's for greedy amateur players like myself.

48:45That's always been a good strategy.

48:47You just build up a lot of money,

48:49and it just feels good to just accumulate and accumulate.

48:53So thank you for discovering that and validating all of us.

48:56But is there other strategies that you discovered

48:59that are interesting, unique to this game?

49:01Yeah, so if you look at the kind of,

49:05not being a StarCraft II player,

49:06but of course StarCraft and StarCraft II

49:08and real time strategy games in general are very similar.

49:12I would classify perhaps the openings of the game.

49:17They're very important.

49:18And generally I would say there's two kinds of openings.

49:21One that's a standard opening.

49:23That's generally how players find sort of a balance

49:28between risk and economy and building some units early on

49:32so that they could defend,

49:34but they're not too exposed basically,

49:36but also expanding quite quickly.

49:38So this would be kind of a standard opening.

49:41And within a standard opening,

49:43then what you do choose generally is

49:45what technology are you aiming towards?

49:47So there's a bit of rock, paper, scissors

49:49of you could go for spaceships

49:52or you could go for invisible units

49:54or you could go for, I don't know,

49:55like massive units that attack against certain kinds

49:58of units, but they're weak against others.

50:01So standard openings themselves have some choices

50:05like rock, paper, scissors style.

50:06Of course, if you scout and you're good

50:08at guessing what the opponent is doing,

50:10then you can play as an advantage

50:12because if you know you're gonna play rock,

50:13I mean, I'm gonna play paper obviously.

50:15So you can imagine that normal standard games

50:18in StarCraft looks like a continuous rock, paper,

50:22scissors game where you guess what the distribution

50:26of rock, paper, and scissors is from the enemy

50:29and reacting accordingly to try to beat it

50:32or put the paper out before he kind of changes his mind

50:36from rock to scissors,

50:38and then you would be in a weak position.

50:39So, sorry to pause on that.

50:41I didn't realize this element

50:42because I know it's true with poker.

50:44I know I looked at Labratus.

50:48So you're also estimating trying to guess the distribution,

50:51trying to better and better estimate the distribution

50:53of what the opponent is likely to be doing.

50:55Yeah, I mean, as a player,

50:56you definitely wanna have a belief state

50:59over what's up on the other side of the map.

51:02And when your belief state becomes inaccurate,

51:05when you start having that serious doubts,

51:07whether he's gonna play something that you must know,

51:10that's when you scout.

51:11You wanna then gather information, right?

51:14Is improving the accuracy of the belief

51:15or improving the belief state part of the loss

51:19that you're trying to optimize?

51:20Or is it just a side effect?

51:22It's implicit, but you could explicitly model it,

51:25and it would be quite good at probably predicting

51:27what's on the other side of the map.

51:30But so far, it's all implicit.

51:32There's no additional reward for predicting the enemy.

51:36So there's these standard openings,

51:38and then there's what people call cheese,

51:41which is very interesting.

51:42And AlphaStar sometimes really likes this kind of cheese.

51:46These cheeses, what they are is kind of an all in strategy.

51:50You're gonna do something sneaky.

51:53You're gonna hide your own buildings

51:56close to the enemy base,

51:58or you're gonna go for hiding your technological buildings

52:01so that you do invisible units

52:03and the enemy just cannot react to detect it

52:06and thus lose the game.

52:07And there's quite a few of these cheeses

52:10and variants of them.

52:11And there it's where actually the belief state

52:14becomes even more important.

52:16Because if I scout your base and I see no buildings at all,

52:20any human player knows something's up.

§07Transcript · 52:22–1:01:04

52:22They might know, well,

52:23you're hiding something close to my base.

52:25Should I build suddenly a lot of units to defend?

52:28Should I actually block my ramp with workers

52:31so that you cannot come and destroy my base?

52:33So there's all this is happening

52:35and defending against cheeses is extremely important.

52:39And in the AlphaStar League,

52:40many agents actually develop some cheesy strategies.

52:45And in the games we saw against TLO and Mana,

52:48two out of the 10 agents

52:49were actually doing these kind of strategies

52:51which are cheesy strategies.

52:53And then there's a variant of cheesy strategy

52:55which is called all in.

52:57So an all in strategy is not perhaps as drastic as,

53:00oh, I'm gonna build cannons on your base

53:02and then bring all my workers

53:03and try to just disrupt your base and game over,

53:06or GG as we say in StarCraft.

53:09There's these kind of very cool things

53:11that you can align precisely at a certain time mark.

53:14So for instance,

53:15you can generate exactly 10 unit composition

53:19that is perfect, like five of this type,

53:21five of this other type,

53:22and align the upgrade

53:24so that at four minutes and a half, let's say,

53:27you have these 10 units and the upgrade just finished.

53:30And at that point, that army is really scary.

53:33And unless the enemy really knows what's going on,

53:36if you push, you might then have an advantage

53:40because maybe the enemy is doing something more standard,

53:42it expanded too much, it developed too much economy,

53:45and it trade off badly against having defenses,

53:49and the enemy will lose.

53:51But it's called all in because if you don't win,

53:53then you're gonna lose.

53:55So you see players that do these kinds of strategies,

53:57if they don't succeed, game is not over.

54:00I mean, they still have a base

54:01and they still gathering minerals,

54:02but they will just GG out of the game

54:04because they know, well, game is over.

54:06I gambled and I failed.

54:08So if we start entering the game theoretic aspects

54:12of the game, it's really rich and it's really,

54:15that's why it also makes it quite entertaining to watch.

54:17Even if I don't play, I still enjoy watching the game.

54:21But the agents are trying to do this mostly implicitly.

54:26But one element that we improved in self play

54:29is creating the Alpha Star League.

54:31And the Alpha Star League is not pure self play.

54:34It's trying to create a different personalities of agents

54:37so that some of them will become cheesy agents.

54:41Some of them might become very economical, very greedy,

54:44like getting all the resources,

54:46but then being maybe early on, they're gonna be weak,

54:48but later on, they're gonna be very strong.

54:51And by creating this personality of agents,

54:53which sometimes it just happens naturally

54:55that you can see kind of an evolution of agents

54:58that given the previous generation,

55:00they train against all of them

55:02and then they generate kind of the perfect counter

55:04to that distribution.

55:05But these agents, you must have them in the populations

55:09because if you don't have them,

55:11you're not covered against these things.

55:13You wanna create all sorts of the opponents

55:17that you will find in the wild.

55:18So you can be exposed to these cheeses, early aggression,

55:23later aggression, more expansions,

55:25dropping units in your base from the side, all these things.

55:29And pure self play is getting a bit stuck

55:32at finding some subset of these, but not all of these.

55:36So the Alpha Star League is a way

55:38to kind of do an ensemble of agents

55:41that they're all playing in a league,

55:43much like people play on Battle.net, right?

55:45They play, you play against someone

55:47who does a new cool strategy and you immediately,

55:50oh my God, I wanna try it, I wanna play again.

55:53And this to me was another critical part of the problem,

55:57which was, can we create a Battle.net for agents?

56:01And that's kind of what the Alpha Star League really is.

56:03That's fascinating.

56:04And where they stick to their different strategies.

56:06Yeah, wow, that's really, really interesting.

56:09But that said, you were fortunate enough

56:13or just skilled enough to win five, zero.

56:17And so how hard is it to win?

56:19I mean, that's not the goal.

56:20I guess, I don't know what the goal is.

56:21The goal should be to win majority, not five, zero,

56:25but how hard is it in general to win all matchups

56:29on a one V one?

56:31So that's a very interesting question

56:33because once you see Alpha Star and superficially

56:38you think, well, okay, it won.

56:40Let's, if you sum all the games like 10 to one, right?

56:42It lost the game that it played with the camera interface.

56:46You might think, well, that's done, right?

56:48It's superhuman at the game.

56:50And that's not really the claim we really can make actually.

56:55The claim is we beat a professional gamer

56:58for the first time.

57:00StarCraft has really been a thing

57:02that has been going on for a few years,

57:04but a moment like this had not occurred before yet.

57:09But are these agents impossible to beat?

57:12Absolutely not, right?

57:13So that's a bit what's kind of the difference is

57:17the agents play at grandmaster level.

57:19They definitely understand the game enough

57:21to play extremely well, but are they unbeatable?

57:24Do they play perfect?

57:26No, and actually in StarCraft,

57:29because of these sneaky strategies,

57:32it's always possible that you might take a huge risk

57:34sometimes, but you might get wins, right?

57:36Out of this.

57:38So I think that as a domain,

57:41it still has a lot of opportunities,

57:43not only because of course we wanna learn

57:45with less experience, we would like to,

57:47I mean, if I learned to play Protoss,

57:49I can play Terran and learn it much quicker

57:52than Alpha Star can, right?

57:53So there are obvious interesting research challenges

57:56as well, but even as the raw performance goes,

58:02really the claim here can be we are at pro level

58:05or at high grandmaster level,

58:08but obviously the players also did not know what to expect,

58:13right?

58:14Their prior distribution was a bit off

58:15because they played this kind of new like alien brain

58:19as they like to say it, right?

58:21And that's what makes it exciting for them.

58:24But also I think if you look at the games closely,

58:27you see there were weaknesses in some points,

58:30maybe Alpha Star did not scout,

58:32or if it had invisible units going against

58:35at certain points, it wouldn't have known

58:37and it would have been bad.

58:38So there's still quite a lot of work to do,

58:42but it's really a very exciting moment for us

58:44to be seeing, wow, a single neural net on a GPU

58:48is actually playing against these guys

58:50who are amazing.

58:51I mean, you have to see them play in life.

58:52They're really, really amazing players.

58:55Yeah, I'm sure there must be a guy in Poland

58:59somewhere right now training his butt off

59:02to make sure that this never happens again with Alpha Star.

59:05So that's really exciting in terms of Alpha Star

59:09having some holes to exploit, which is great.

59:11And then we build on top of each other

59:13and it feels like StarCraft on let go,

59:16even if you win, it's still not,

59:20there's so many different dimensions

59:23in which you can explore.

59:24So that's really, really interesting.

59:25Do you think there's a ceiling to Alpha Star?

59:28You've said that it hasn't reached,

59:31you know, this is a big,

59:32wait, let me actually just pause for a second.

59:35How did it feel to come here to this point,

59:40to beat a top professional player?

59:42Like that night, I mean, you know,

59:44Olympic athletes have their gold medal, right?

59:47This is your gold medal in a sense.

59:48Sure, you're cited a lot,

59:50you've published a lot of prestigious papers, whatever,

59:53but this is like a win.

59:55How did it feel?

59:56I mean, it was, for me, it was unbelievable

59:59because first the win itself,

60:03I mean, it was so exciting.

60:05I mean, so looking back to those last days of 2018 really,

60:11that's when the games were played.

60:13I'm sure I look back at that moment, I'll say,

60:15oh my God, I want to be in a project like that.

60:18It's like, I already feel the nostalgia of like,

60:21yeah, that was huge in terms of the energy

60:24and the team effort that went into it.

60:26And so in that sense, as soon as it happened,

60:29I already knew it was kind of,

60:31I was losing it a little bit.

60:33So it is almost like sad that it happened and oh my God,

60:36but on the other hand, it also verifies the approach.

60:41But to me also, there's so many challenges

60:43and interesting aspects of intelligence

60:46that even though we can train a neural network

60:49to play at the level of the best humans,

60:52there's still so many challenges.

60:54So for me, it's also like, well,

60:55this is really an amazing achievement,

60:57but I already was also thinking about next steps.

60:59I mean, as I said, these Asians play Protoss versus Protoss,

§08Transcript · 1:01:04–1:10:23

61:04but they should be able to play a different race

61:07much quicker, right?

61:08So that would be an amazing achievement.

61:10Some people call this meta reinforcement learning,

61:13meta learning and so on, right?

61:15So there's so many possibilities after that moment,

61:18but the moment itself, it really felt great.

61:23We had this bet, so I'm kind of a pessimist in general.

61:27So I kind of send an email to the team.

61:29I said, okay, let's against TLO first, right?

61:33Like what's gonna be the result?

61:35And I really thought we would lose like five zero, right?

61:38We had some calibration made against the 5,000 MMR player.

61:44TLO was much stronger than that player,

61:47even if he played Protoss, which is his off race.

61:51But yeah, I was not imagining we would win.

61:53So for me, that was just kind of a test run or something.

61:55And then it really kind of, he was really surprised.

61:59And unbelievably, we went to this bar to celebrate

62:04and Dave tells me, well, why don't we invite someone

62:08who is a thousand MMR stronger in Protoss,

62:10like actual Protoss player,

62:12like that it turned up being Mana, right?

62:16And we had some drinks and I said, sure, why not?

62:19But then I thought, well,

62:20that's really gonna be impossible to beat.

62:22I mean, even because it's so much ahead,

62:24a thousand MMR is really like 99% probability

62:28that Mana would beat TLO as Protoss versus Protoss, right?

62:33So we did that.

62:34And to me, the second game was much more important,

62:38even though a lot of uncertainty kind of disappeared

62:42after we kind of beat TLO.

62:43I mean, he is a professional player.

62:45So that was kind of, oh,

62:46but that's really a very nice achievement.

62:49But Mana really was at the top

62:51and you could see he played much better,

62:53but our agents got much better too.

62:55So it's like, ah, and then after the first game,

62:59I said, if we take a single game,

63:00at least we can say we beat a game.

63:02I mean, even if we don't beat the series,

63:04for me, that was a huge relief.

63:06And I mean, I remember the hugging demis.

63:09And I mean, it was really like,

63:10this moment for me will resonate forever as a researcher.

63:14And I mean, as a person,

63:15and yeah, it's a really like great accomplishment.

63:18And it was great also to be there with the team in the room.

63:21I don't know if you saw like this.

63:23So it was really like.

63:24I mean, from my perspective,

63:25the other interesting thing is just like watching Kasparov,

63:29watching Mana was also interesting

63:33because he didn't, he has kind of a loss of words.

63:36I mean, whenever you lose, I've done a lot of sports.

63:38You sometimes say excuses, you look for reasons.

63:43And he couldn't really come up with reasons.

63:46I mean, so with the off race for Protoss,

63:50you could say, well, it felt awkward, it wasn't,

63:52but here it was just beaten.

63:55And it was beautiful to look at a human being

63:57being superseded by an AI system.

64:00I mean, it's a beautiful moment for researchers, so.

64:04Yeah, for sure it was.

64:05I mean, probably the highlight of my career so far

64:09because of its uniqueness and coolness.

64:11And I don't know, I mean, it's obviously, as you said,

64:14you can look at papers, citations and so on,

64:16but these really is like a testament

64:19of the whole machine learning approach

64:22and using games to advance technology.

64:24I mean, it really was,

64:26everything came together at that moment.

64:28That's really the summary.

64:29Also on the other side, it's a popularization of AI too,

64:34because it's just like traveling to the moon and so on.

64:38I mean, this is where a very large community of people

64:41that don't really know AI,

64:43they get to really interact with it.

64:45Which is very important.

64:46I mean, we must, you know,

64:48writing papers helps our peers, researchers,

64:51to understand what we're doing.

64:52But I think AI is becoming mature enough

64:55that we must sort of try to explain what it is.

64:59And perhaps through games is an obvious way

65:01because these games always had built in AI.

65:03So it may be everyone experience an AI playing a video game,

65:07even if they don't know,

65:08because there's always some scripted element

65:10and some people might even call that AI already, right?

65:13So what are other applications

65:16of the approaches underlying AlphaStar

65:19that you see happening?

65:20There's a lot of echoes of, you said,

65:22transformer of language modeling and so on.

65:25Have you already started thinking

65:27where the breakthroughs in AlphaStar

65:30get expanded to other applications?

65:32Right, so I thought about a few things

65:34for like kind of next month, next years.

65:38The main thing I'm thinking about actually is what's next

65:41as a kind of a grand challenge.

65:43Because for me, like we've seen Atari

65:47and then there's like the sort of three dimensional walls

65:50that we've seen also like pretty good performance

65:52from these capture the flag agents

65:54that also some people at DeepMind and elsewhere

65:56are working on.

65:57We've also seen some amazing results on like,

65:59for instance, Dota 2, which is also a very complicated game.

66:03So for me, like the main thing I'm thinking about

66:05is what's next in terms of challenge.

66:07So as a researcher, I see sort of two tensions

66:12between research and then applications or areas

66:16or domains where you apply them.

66:18So on the one hand, we've done,

66:20thanks to the application of StarCraft is very hard.

66:23We developed some techniques, some new research

66:25that now we could look at elsewhere.

66:27Like are there other applications where we can apply these?

66:30And the obvious ones, absolutely.

66:32You can think of feeding back to sort of the community

66:37we took from, which was mostly sequence modeling

66:40or natural language processing.

66:41So we've developed and extended things from the transformer

66:46and we use pointer networks.

66:48We combine LSTM and transformers in interesting ways.

66:51So that's perhaps the kind of lowest hanging fruit

66:54of feeding back to now a different field

66:57of machine learning that's not playing video games.

67:00Let me go old school and jump to Mr. Alan Turing.

67:05So the Turing test is a natural language test,

67:09a conversational test.

67:11What's your thought of it as a test for intelligence?

67:15Do you think it is a grand challenge

67:17that's worthy of undertaking?

67:18Maybe if it is, would you reformulate it or phrase it

67:22somehow differently?

67:23Right, so I really love the Turing test

67:25because I also like sequences and language understanding.

67:29And in fact, some of the early work

67:32we did in machine translation, we

67:33tried to apply to kind of a neural chatbot, which obviously

67:38would never pass the Turing test because it was very limited.

67:42But it is a very fascinating idea

67:45that you could really have an AI that

67:49would be indistinguishable from humans in terms of asking

67:53or conversing with it.

67:56So I think the test itself seems very nice.

68:00And it's kind of well defined, actually,

68:02like the passing it or not.

68:04I think there's quite a few rules

68:06that feel pretty simple.

68:09And I think they have these competitions every year.

68:14Yes, there's the Lebner Prize.

68:15But I don't know if you've seen the kind of bots

68:22that emerge from that competition.

68:24They're not quite as what you would.

68:27So it feels like that there's weaknesses with the way Turing

68:30formulated it.

68:31It needs to be that the definition

68:34of a genuine, rich, fulfilling human conversation,

68:39it needs to be something else.

68:41Like the Alexa Prize, which I'm not as well familiar with,

68:44has tried to define that more, I think,

68:46by saying you have to continue keeping

68:48a conversation for 30 minutes, something like that.

68:52So basically forcing the agent not to just fool,

68:55but to have an engaging conversation kind of thing.

69:02Have you thought about this problem richly?

69:06And if you have in general, how far away are we from?

69:10You worked a lot on language understanding,

69:14language generation, but the full dialogue,

69:16the conversation, just sitting at the bar

69:19having a couple of beers for an hour,

69:21that kind of conversation.

69:22Have you thought about it?

69:23Yeah, so I think you touched here

69:25on the critical point, which is feasibility.

69:28So there's a great essay by Hamming,

69:32which describes sort of grand challenges of physics.

69:37And he argues that, well, OK, for instance,

69:41teleportation or time travel are great grand challenges

69:44of physics, but there's no attacks.

69:46We really don't know or cannot kind of make any progress.

69:50So that's why most physicists and so on,

69:53they don't work on these in their PhDs

69:55and as part of their careers.

69:57So I see the Turing test, in the full Turing test,

70:00as a bit still too early.

70:02Like I think we're, especially with the current trend

70:06of deep learning language models,

70:10we've seen some amazing examples.

70:11I think GPT2 being the most recent one, which

70:14is very impressive.

70:15But to understand to fully solve passing or fooling a human

70:21to think that there's a human on the other side,

§09Transcript · 1:10:23–1:19:59

70:23I think we're quite far.

70:24So as a result, I don't see myself

70:27and I probably would not recommend people doing a PhD

70:30on solving the Turing test because it just

70:32feels it's kind of too early or too hard of a problem.

70:35Yeah, but that said, you said the exact same thing

70:37about StarCraft about a few years ago.

70:40Indeed.

70:41To Demis.

70:41So you'll probably also be the person who passes

70:46the Turing test in three years.

70:48I mean, I think that, yeah.

70:50So we have this on record.

70:52This is nice.

70:52It's true.

70:53I mean, it's true that progress sometimes

70:56is a bit unpredictable.

70:57I really wouldn't have not.

70:59Even six months ago, I would not have predicted the level

71:02that we see that these agents can deliver at grandmaster

71:06level.

71:07But I have worked on language enough.

71:10And basically, my concern is not that something could happen,

71:13a breakthrough could happen that would bring us to solving

71:16or passing the Turing test, is that I just

71:19think the statistical approach to it is not going to cut it.

71:24So we need a breakthrough, which is great for the community.

71:28But given that, I think there's quite more uncertainty.

71:31Whereas for StarCraft, I knew what the steps would

71:36be to get us there.

71:38I think it was clear that using the imitation learning part

71:41and then using this battle net for agents

71:44were going to be key.

71:45And it turned out that this was the case.

71:48And a little more was needed, but not much more.

71:51For Turing test, I just don't know

71:53what the plan or execution plan would look like.

71:56So that's why I myself working on it as a grand challenge

72:00is hard.

72:01But there are quite a few sub challenges

72:03that are related that you could say,

72:05well, I mean, what if you create a great assistant

72:09like Google already has, like the Google Assistant.

72:11So can we make it better?

72:13And can we make it fully neural and so on?

72:15That I start to believe maybe we're

72:17reaching a point where we should attempt these challenges.

72:20I like this conversation so much because it echoes very much

72:23the StarCraft conversation.

72:24It's exactly how you approach StarCraft.

72:26Let's break it down into small pieces and solve those.

72:29And you end up solving the whole game.

72:31Great.

72:31But that said, you're behind some

72:34of the biggest pieces of work in deep learning

72:37in the last several years.

72:40So you mentioned some limits.

72:42What do you think of the current limits of deep learning?

72:44And how do we overcome those limits?

72:47So if I had to actually use a single word

72:50to define the main challenge in deep learning,

72:53it's a challenge that probably has

72:55been the challenge for many years.

72:56And it's that of generalization.

72:59So what that means is that all that we're doing

73:04is fitting functions to data.

73:06And when the data we see is not from the same distribution,

73:12or even if there are some times that it

73:14is very close to distribution, but because

73:17of the way we train it with limited samples,

73:20we then get to this stage where we just

73:23don't see generalization as much as we can generalize.

73:27And I think adversarial examples are a clear example of this.

73:31But if you study machine learning and literature,

73:34and the reason why SVMs came very popular

73:38were because they were dealing and they

73:40had some guarantees about generalization, which

73:42is unseen data or out of distribution,

73:45or even within distribution where you take an image adding

73:48a bit of noise, these models fail.

73:51So I think, really, I don't see a lot of progress

73:56on generalization in the strong generalization

74:00sense of the word.

74:01I think our neural networks, you can always

74:05find design examples that will make their outputs arbitrary,

74:11which is not good because we humans would never

74:15be fooled by these kind of images

74:17or manipulation of the image.

74:19And if you look at the mathematics,

74:21you kind of understand this is a bunch of matrices

74:23multiplied together.

74:26There's probably numerics and instability

74:28that you can just find corner cases.

74:30So I think that's really the underlying topic many times

74:35we see when even at the grand stage of Turing test

74:40generalization, if you start passing the Turing test,

74:44should it be in English or should it be in any language?

74:48As a human, if you ask something in a different language,

74:53you actually will go and do some research

74:54and try to translate it and so on.

74:57Should the Turing test include that?

75:01And it's really a difficult problem

75:02and very fascinating and very mysterious, actually.

75:05Yeah, absolutely.

75:06But do you think if you were to try to solve it,

75:10can you not grow the size of data intelligently

75:14in such a way that the distribution of your training

75:17set does include the entirety of the testing set?

75:20Is that one path?

75:21The other path is totally a new methodology.

75:23It's not statistical.

75:24So a path that has worked well, and it worked well

75:27in StarCraft and in machine translation and in languages,

75:30scaling up the data and the model.

75:32And that's kind of been maybe the only single formula that

75:38still delivers today in deep learning, right?

75:40It's that data scale and model scale really

75:44do more and more of the things that we thought,

75:47oh, there's no way it can generalize to these,

75:49or there's no way it can generalize to that.

75:51But I don't think fundamentally it will be solved with this.

75:54And for instance, I'm really liking some style or approach

75:59that would not only have neural networks,

76:02but it would have programs or some discrete decision making,

76:06because there is where I feel there's a bit more.

76:10I mean, the best example, I think, for understanding this

76:13is I also worked a bit on, oh, we

76:16can learn an algorithm with a neural network, right?

76:18So you give it many examples, and it's

76:20going to sort the input numbers or something like that.

76:24But really strong generalization is you give me some numbers

76:29or you ask me to create an algorithm that sorts numbers.

76:32And instead of creating a neural net, which will be fragile

76:34because it's going to go out of range at some point,

76:37you're going to give it numbers that are too large, too small,

76:40and whatnot, if you just create a piece of code that

76:45sorts the numbers, then you can prove

76:47that that will generalize to absolutely all the possible

76:50input you could give.

76:51So I think the problem comes with some exciting prospects.

76:55I mean, scale is a bit more boring, but it really works.

76:59And then maybe programs and discrete abstractions

77:02are a bit less developed.

77:04But clearly, I think they're quite exciting in terms

77:07of future for the field.

77:09Do you draw any insight wisdom from the 80s and expert

77:14systems and symbolic systems, symbolic computing?

77:16Do you ever go back to those reasoning, that kind of logic?

77:20Do you think that might make a comeback?

77:23You'll have to dust off those books?

77:24Yeah, I actually love actually adding more inductive biases.

77:31To me, the problem really is, what are you trying to solve?

77:34If what you're trying to solve is so important that try

77:37to solve it no matter what, then absolutely use rules,

77:42use domain knowledge, and then use

77:45a bit of the magic of machine learning

77:46to empower to make the system as the best system that

77:50will detect cancer or detect weather patterns, right?

77:56Or in terms of StarCraft, it also was a very big challenge.

77:59So I was definitely happy that if we

78:01had to cut a corner here and there,

78:04it could have been interesting to do.

78:07And in fact, in StarCraft, we start

78:09thinking about expert systems because it's a very,

78:11you know, you can define.

78:12I mean, people actually build StarCraft bots by thinking

78:15about those principles, like state machines and rule based.

78:20And then you could think of combining

78:22a bit of a rule based system, but that has also

78:25neural networks incorporated to make it generalize a bit

78:28better.

78:29So absolutely, I mean, we should definitely

78:31go back to those ideas.

78:32And anything that makes the problem simpler,

78:35as long as your problem is important, that's OK.

78:37And that's research driving a very important problem.

78:41And on the other hand, if you want to really focus

78:44on the limits of reinforcement learning,

78:46then of course, you must try not to look at imitation data

78:50or to look for some rules of the domain that would help a lot

78:55or even feature engineering, right?

78:56So this is a tension that depending on what you do,

79:00I think both ways are definitely fine.

79:03And I would never not do one or the other

79:06as long as what you're doing is important

79:08and needs to be solved, right?

79:10Right, so there's a bunch of different ideas

79:13that you developed that I really enjoy.

79:16But one is translating from image captioning,

79:22translating from image to text, just another beautiful idea,

79:27I think, that resonates throughout your work, actually.

79:33So the underlying nature of reality

79:35being language always, somehow.

79:38So what's the connection between images and text,

79:42or rather the visual world and the world

79:44of language in your view?

79:46Right, so I think a piece of research that's been central

79:51to, I would say, even extending into StarGraph

79:54is this idea of sequence to sequence learning,

79:57which what we really meant by that

§10Transcript · 1:19:59–1:29:33

79:59is that you can now really input anything

80:03to a neural network as the input x.

80:06And then the neural network will learn a function f

80:09that will take x as an input and produce any output y.

80:12And these x and y's don't need to be static or features,

80:19like fixed vectors or anything like that.

80:22It could be really sequences and now beyond data structures.

80:26So that paradigm was tested in a very interesting way

80:31when we moved from translating French to English

80:35to translating an image to its caption.

80:37But the beauty of it is that, really,

80:40and that's actually how it happened.

80:43I changed a line of code in this thing that

80:45was doing machine translation.

80:47And I came the next day, and I saw

80:50how it was producing captions that seemed like, oh my god,

80:54this is really, really working.

80:55And the principle is the same.

80:57So I think I don't see text, vision, speech, waveforms

81:04as something different as long as you basically

81:09learn a function that will vectorize these into.

81:14And then after we vectorize it, we

81:16can then use transformers, LSTMs, whatever

81:20the flavor of the month of the model is.

81:22And then as long as we have enough supervised data,

81:25really, this formula will work and will keep working,

81:30I believe, to some extent.

81:31Modulo these generalization issues that I mentioned before.

81:35But the task there is to vectorize,

81:36so to form a representation that's meaningful.

81:39And your intuition now, having worked with all this media,

81:42is that once you are able to form that representation,

81:46you could basically take any things, any sequence.

81:51Going back to StarCraft, is there

81:52limits on the length so that we didn't really

81:56touch on the long term aspect?

81:59How did you overcome the whole really long term

82:02aspect of things here?

82:03Is there some tricks?

82:05So the main trick, so StarCraft, if you

82:08look at absolutely every frame, you

82:10might think it's quite a long game.

82:12So we would have to multiply 22 times 60 seconds per minute

82:18times maybe at least 10 minutes per game on average.

82:21So there are quite a few frames.

82:25But the trick really was to only observe, in fact,

82:30which might be seen as a limitation,

82:32but it is also a computational advantage.

82:35Only observe when you act.

82:37And then what the neural network decides

82:40is what is the gap going to be until the next action.

82:44And if you look at most StarCraft games

82:48that we have in the data set that Blizzard provided,

82:51it turns out that most games are actually only,

82:56I mean, it is still a long sequence,

82:58but it's maybe like 1,000 to 1,500 actions,

83:02which if you start looking at LSTMs, large LSTMs,

83:07transformers, it's not that difficult, especially

83:12if you have supervised learning.

83:14If you had to do it with reinforcement learning,

83:16the credit assignment problem, what

83:18is it in this game that made you win?

83:19That would be really difficult.

83:21But thankfully, because of imitation learning,

83:24we didn't have to deal with these directly.

83:27Although if we had to, we tried it.

83:29And what happened is you just take all your workers

83:31and attack with them.

83:33And that is kind of obvious in retrospect

83:36because you start trying random actions.

83:38One of the actions will be a worker

83:40that goes to the enemy base.

83:41And because it's self play, it's not

83:43going to know how to defend because it basically

83:45doesn't know almost anything.

83:47And eventually, what you develop is this take all workers

83:50and attack because the credit assignment issue in a rally

83:54is really, really hard.

83:55I do believe we could do better.

83:57And that's maybe a research challenge for the future.

84:01But yeah, even in StarCraft, the sequences

84:04are maybe 1,000, which I believe is

84:07within the realm of what transformers can do.

84:10Yeah, I guess the difference between StarCraft and Go

84:12is in Go and Chess, stuff starts happening right away.

84:18So there's not, yeah, it's pretty easy to self play.

84:22Not easy, but to self play, it's possible to develop

84:24reasonable strategies quickly as opposed to StarCraft.

84:27I mean, in Go, there's only 400 actions.

84:30But one action is what people would call the God action.

84:34That would be if you had expanded the whole search

84:38tree, that's the best action if you did minimax

84:40or whatever algorithm you would do if you

84:42had the computational capacity.

84:44But in StarCraft, 400 is minuscule.

84:48Like in 400, you couldn't even click

84:51on the pixels around a unit.

84:53So I think the problem there is in terms of action space size

84:58is way harder.

85:01And that search is impossible.

85:03So there's quite a few challenges indeed

85:06that make this kind of a step up in terms of machine learning.

85:10For humans, maybe playing StarCraft

85:13seems more intuitive because it looks real.

85:16I mean, the graphics and everything moves smoothly,

85:18whereas I don't know how to.

85:20I mean, Go is a game that I would really need to study.

85:22It feels quite complicated.

85:23But for machines, kind of maybe it's the reverse, yes.

85:27Which shows you the gap actually between deep learning

85:30and however the heck our brains work.

85:34So you developed a lot of really interesting ideas.

85:36It's interesting to just ask, what's

85:38your process of developing new ideas?

85:41Do you like brainstorming with others?

85:42Do you like thinking alone?

85:44Do you like, what was it, Ian Goodfellow said

85:49he came up with GANs after a few beers.

85:52He thinks beers are essential for coming up with new ideas.

85:55We had beers to decide to play another game of StarCraft

85:59after a week.

85:59So it's really similar to that story.

86:02Actually, I explained this in a DeepMind retreat.

86:05And I said, this is the same as the GAN story.

86:08I mean, we were in a bar.

86:09And we decided, let's play a GAN next week.

86:10And that's what happened.

86:11I feel like we're giving the wrong message

86:13to young undergrads.

86:15Yeah, I know.

86:15But in general, do you like brainstorming?

86:18Do you like thinking alone, working stuff out?

86:20So I think throughout the years, also, things changed.

86:23So initially, I was very fortunate to be

86:29with great minds like Jeff Hinton, Jeff Dean,

86:33Ilya Sutskever.

86:34I was really fortunate to join Brain at a very good time.

86:37So at that point, ideas, I was just

86:41brainstorming with my colleagues and learned a lot.

86:44And keep learning is actually something

86:46you should never stop doing.

86:48So learning implies reading papers and also

86:51discussing ideas with others.

86:53It's very hard at some point to not communicate

86:56that being reading a paper from someone

86:59or actually discussing.

87:00So definitely, that communication aspect

87:04needs to be there, whether it's written or oral.

87:08Nowadays, I'm also trying to be a bit more strategic

87:12about what research to do.

87:15So I was describing a little bit this tension

87:18between research for the sake of research,

87:21and then you have, on the other hand,

87:23applications that can drive the research.

87:25And honestly, the formula that has worked best for me

87:28is just find a hard problem and then

87:32try to see how research fits into it,

87:34how it doesn't fit into it, and then you must innovate.

87:37So I think machine translation drove sequence to sequence.

87:43Then maybe learning algorithms that had to,

87:47combinatorial algorithms led to pointer networks.

87:50StarCraft led to really scaling up imitation learning

87:53and the AlphaStarLeague.

87:55So that's been a formula that I personally like.

87:58But the other one is also valid.

88:00And I've seen it succeed a lot of the times

88:02where you just want to investigate model based

88:05RL as a research topic.

88:08And then you must then start to think, well,

88:11how are the tests?

88:12How are you going to test these ideas?

88:14You need a minimal environment to try things.

88:17You need to read a lot of papers and so on.

88:19And that's also very fun to do and something

88:21I've also done quite a few times,

88:24both at Brain, at DeepMind, and obviously as a PhD.

88:28So I think besides the ideas and discussions,

88:32I think it's important also because you start

88:35sort of guiding not only your own goals,

88:40but other people's goals to the next breakthrough.

88:44So you must really kind of understand this feasibility

88:48also, as we were discussing before,

88:50whether this domain is ready to be tackled or not.

88:53And you don't want to be too early.

88:55You obviously don't want to be too late.

88:57So it's really interesting, this strategic component

89:00of research, which I think as a grad student,

89:03I just had no idea.

89:05I just read papers and discussed ideas.

89:07And I think this has been maybe the major change.

89:09And I recommend people kind of feed forward

89:13to success how it looks like and try to backtrack,

89:16other than just kind of looking, oh, this looks cool.

89:18This looks cool.

89:19And then you do a bit of random work,

89:21which sometimes you stumble upon some interesting things.

89:23But in general, it's also good to plan a bit.

89:27Yeah, I like it.

89:28Especially like your approach of taking a really hard problem,

89:31stepping right in, and then being

§11Transcript · 1:29:33–1:38:59

89:33super skeptical about being able to solve the problem.

89:37I mean, there's a balance of both, right?

89:40There's a silly optimism and a critical sort of skepticism

89:46that's good to balance, which is why

89:49it's good to have a team of people that balance that.

89:52You don't do that on your own.

89:53You have both mentors that have seen,

89:56or you obviously want to chat and discuss

89:59whether it's the right time.

90:00I mean, Demis came in 2014.

90:03And he said, maybe in a bit we'll do StarCraft.

90:06And maybe he knew.

90:08And I'm just following his lead, which is great,

90:11because he's brilliant, right?

90:12So these things are obviously quite important,

90:17that you want to be surrounded by people who are diverse.

90:22They have their knowledge.

90:23There's also important to, I mean,

90:26I've learned a lot from people who actually have an idea

90:30that I might not think it's good.

90:32But if I give them the space to try it,

90:34I've been proven wrong many, many times as well.

90:37So that's great.

90:38I think your colleagues are more important than yourself,

90:42I think.

90:43Sure.

90:44Now let's real quick talk about another impossible problem,

90:48AGI.

90:49Right.

90:50What do you think it takes to build a system that's

90:52human level intelligence?

90:54We talked a little bit about the Turing test, StarCraft.

90:56All of these have echoes of general intelligence.

90:58But if you think about just something

91:01that you would sit back and say, wow,

91:03this is really something that resembles

91:06human level intelligence.

91:07What do you think it takes to build that?

91:09So I find that AGI oftentimes is maybe not very well defined.

91:17So what I'm trying to then come up with for myself

91:20is what would be a result look like that you would start

91:25to believe that you would have agents or neural nets that

91:28no longer overfeed to a single task,

91:31but actually learn the skill of learning, so to speak.

91:37And that actually is a field that I

91:40am fascinated by, which is the learning to learn,

91:43or meta learning, which is about no longer learning

91:47about a single domain.

91:48So you can think about the learning algorithm

91:51itself is general.

91:52So the same formula we applied for AlphaStar or StarCraft,

91:56we can now apply to almost any video game,

91:59or you could apply to many other problems and domains.

92:03But the algorithm is what's generalizing.

92:07But the neural network, those weights

92:09are useless even to play another race.

92:12I train a network to play very well at Protos versus Protos.

92:15I need to throw away those weights.

92:17If I want to play now Terran versus Terran,

92:20I would need to retrain a network from scratch

92:23with the same algorithm.

92:24That's beautiful.

92:26But the network itself will not be useful.

92:28So I think if I see an approach that

92:32can absorb or start solving new problems without the need

92:38to kind of restart the process, I

92:40think that, to me, would be a nice way

92:42to define some form of AGI.

92:45Again, I don't know the grandiose like age.

92:48I mean, should Turing tests be solved before AGI?

92:50I mean, I don't know.

92:51I think concretely, I would like to see clearly

92:54that meta learning happen, meaning

92:57that there is an architecture or a network that

93:01as it sees new problem or new data, it solves it.

93:04And to make it kind of a benchmark,

93:08it should solve it at the same speed

93:09that we do solve new problems.

93:11When I define you a new object and you

93:13have to recognize it, when you start playing a new game,

93:16you played all the Atari games.

93:17But now you play a new Atari game.

93:19Well, you're going to be pretty quickly pretty good

93:22at the game.

93:22So that's perhaps what's the domain

93:25and what's the exact benchmark is a bit difficult.

93:28I think as a community, we might need

93:29to do some work to define it.

93:32But I think this first step, I could

93:34see it happen relatively soon.

93:36But then the whole what AGI means and so on,

93:40I am a bit more confused about what

93:43I think people mean different things.

93:44There's an emotional, psychological level

93:48that like even the Turing test, passing the Turing test

93:53is something that we just pass judgment on as human beings

93:55what it means to be as a dog in AGI system.

94:03Yeah.

94:04What level, what does it mean, what does it mean?

94:07But I like the generalization.

94:08And maybe as a community, we converge

94:10towards a group of domains that are sufficiently far away.

94:14That would be really damn impressive

94:16if it was able to generalize.

94:18So perhaps not as close as Protoss and Zerg,

94:21but like Wikipedia.

94:22That would be a step.

94:23Yeah, that would be a good step and then a really good step.

94:26But then like from StarCraft to Wikipedia and back.

94:30Yeah, that kind of thing.

94:31And that feels also quite hard and far.

94:34But I think as long as you put the benchmark out,

94:38as we discovered, for instance, with ImageNet,

94:41then tremendous progress can be had.

94:43So I think maybe there's a lack of benchmark,

94:46but I'm sure we'll find one and the community will then

94:49work towards that.

94:52And then beyond what AGI might mean or would imply,

94:56I really am hopeful to see basically machine learning

95:01or AI just scaling up and helping people

95:05that might not have the resources to hire an assistant

95:08or that they might not even know what the weather is like.

95:13So I think in terms of the positive impact of AI,

95:18I think that's maybe what we should also not lose focus.

95:22The research community building AGI,

95:23I mean, that's a real nice goal.

95:25But I think the way that DeepMind puts it is,

95:28and then use it to solve everything else.

95:30So I think we should paralyze.

95:33Yeah, we shouldn't forget about all the positive things

95:36that are actually coming out of AI already

95:38and are going to be coming out.

95:40Right.

95:41But on that note, let me ask relative

95:45to popular perception, do you have

95:47any worry about the existential threat

95:49of artificial intelligence in the near or far future

95:53that some people have?

95:55I think in the near future, I'm skeptical.

95:58So I hope I'm not wrong.

95:59But I'm not concerned, but I appreciate efforts,

96:04ongoing efforts, and even like whole research

96:07field on AI safety emerging and in conferences and so on.

96:10I think that's great.

96:12In the long term, I really hope we just

96:16can simply have the benefits outweigh

96:19the potential dangers.

96:20I am hopeful for that.

96:23But also, we must remain vigilant to monitor and assess

96:27whether the tradeoffs are there and we have enough also lead

96:32time to prevent or to redirect our efforts if need be.

96:37But I'm quite optimistic about the technology

96:41and definitely more fearful of other threats

96:45in terms of planetary level at this point.

96:48But obviously, that's the one I have more power on.

96:52So clearly, I do start thinking more and more about this.

96:56And it's grown in me actually to start reading more

97:00about AI safety, which is a field that so far I have not

97:04really contributed to.

97:05But maybe there's something to be done there as well.

97:07I think it's really important.

97:09I talk about this with a few folks.

97:11But it's important to ask you and shove it in your head

97:14because you're at the leading edge of actually what

97:18people are excited about in AI.

97:19The work with AlphaStar, it's arguably

97:22at the very cutting edge of the kind of thing

97:25that people are afraid of.

97:27And so you speaking to that fact and that we're actually

97:31quite far away to the kind of thing

97:33that people might be afraid of.

97:35But it's still worthwhile to think about.

97:38And it's also good that you're not as worried

97:43and you're also open to thinking about it.

97:45There's two aspects.

97:46I mean, me not being worried.

97:47But obviously, we should prepare for things

97:53that could go wrong, misuse of the technologies

97:56as with any technologies.

97:58So I think there's always trade offs.

98:02And as a society, we've kind of solved this to some extent

98:06in the past.

98:07So I'm hoping that by having the researchers

98:10and the whole community brainstorm and come up

98:14with interesting solutions to the new things that

98:16will happen in the future, that we can still also push

98:20the research to the avenue that I think

98:23is kind of the greatest avenue, which is

98:25to understand intelligence.

98:27How are we doing what we're doing?

98:29And obviously, from a scientific standpoint,

98:32that is kind of my personal drive of all the time

98:37that I spend doing what I'm doing, really.

98:40Where do you see the deep learning as a field heading?

98:42Where do you think the next big breakthrough might be?

98:46So I think deep learning, I discussed a little of this

98:49before.

98:50Deep learning has to be combined with some form

98:54of discretization, program synthesis.

98:56I think that's kind of as a research in itself

§12Transcript · 1:38:59–1:46:00

98:59is an interesting topic to expand and start

99:02doing more research.

99:04And then as kind of what will deep learning

99:07enable to do in the future?

99:08I don't think that's going to be what's going to happen this year.

99:11But also this idea of starting not to throw away all the weights,

99:16that this idea of learning to learn

99:18and really having these agents not having

99:23to restart their weights.

99:24And you can have an agent that is kind of solving or classifying

99:29images on ImageNet, but also generating speech

99:32if you ask it to generate some speech.

99:34And it should really be kind of almost the same network,

99:39but it might not be a neural network.

99:41It might be a neural network with an optimization

99:44algorithm attached to it.

99:45But I think this idea of generalization to new task

99:49is something that we first must define good benchmarks.

99:52But then I think that's going to be exciting.

99:54And I'm not sure how close we are.

99:56But I think if you have a very limited domain,

100:00I think we can start doing some progress.

100:02And much like how we did a lot of programs in computer vision,

100:07we should start thinking.

100:09I really like a talk that Leon Buto gave at ICML

100:12a few years ago, which is this train test paradigm should

100:16be broken.

100:17We should stop thinking about a training set and a test set.

100:23And these are closed things that are untouchable.

100:26I think we should go beyond these.

100:28And in meta learning, we call these the meta training

100:30set and the meta test set, which is really thinking about,

100:35if I know about ImageNet, why would that network not

100:39work on MNIST, which is a much simpler problem?

100:41But right now, it really doesn't.

100:44But it just feels wrong.

100:46So I think that's kind of the, on the application

100:50or the benchmark sites, we probably

100:52will see quite a few more interest and progress

100:56and hopefully people defining new and exciting challenges

101:00really.

101:00Do you have any hope or interest in knowledge graphs

101:04within this context?

101:05So this kind of constructing graph.

101:08So going back to graphs.

101:10Well, neural networks and graphs.

101:12But I mean, a different kind of knowledge graph,

101:14sort of like semantic graphs or those concepts.

101:18Yeah.

101:18So I think the idea of graphs is,

101:23so I've been quite interested in sequences first and then

101:26more interesting or different data structures like graphs.

101:29And I've studied graph neural networks in the last three

101:33years or so.

101:34I found these models just very interesting

101:37from deep learning sites standpoint.

101:42But then why do we want these models

101:45and why would we use them?

101:47What's the application?

101:48What's kind of the killer application of graphs?

101:51And perhaps if we could extract a knowledge graph

101:58from Wikipedia automatically, that

102:01would be interesting because then these graphs have

102:04this very interesting structure that also is a bit more

102:07compatible with this idea of programs and deep learning

102:11kind of working together, jumping neighborhoods

102:14and so on.

102:14You could imagine defining some primitives

102:17to go around graphs, right?

102:18So I think I really like the idea of a knowledge graph.

102:23And in fact, when we started or as part of the research

102:29we did for StarCraft, I thought, wouldn't it

102:31be cool to give the graph of all these buildings that

102:38depend on each other and units that have prerequisites

102:41of being built by that.

102:42And so this is information that the network

102:45can learn and extract.

102:46But it would have been great to see

102:50or to think of really StarCraft as a giant graph that even

102:53also as the game evolves, you start taking branches

102:57and so on.

102:57And we did a bit of research on these,

102:59nothing too relevant, but I really like the idea.

103:04And it has elements that are something

103:06you also worked with in terms of visualizing your networks.

103:08It has elements of having human interpretable,

103:13being able to generate knowledge representations that

103:15are human interpretable that maybe human experts can then

103:18tweak or at least understand.

103:20So there's a lot of interesting aspect there.

103:22And for me personally, I'm just a huge fan of Wikipedia.

103:25And it's a shame that our neural networks aren't

103:29taking advantage of all the structured knowledge that's

103:31on the web.

103:32What's next for you?

103:34What's next for DeepMind?

103:36What are you excited about for AlphaStar?

103:39Yeah, so I think the obvious next steps

103:43would be to apply AlphaStar to other races.

103:48I mean, that sort of shows that the algorithm works

103:51because we wouldn't want to have created by mistake something

103:56in the architecture that happens to work for Protoss

103:58but not for other races.

104:00So as verification, I think that's an obvious next step

104:03that we are working on.

104:05And then I would like to see so agents and players can

104:11specialize on different skill sets that

104:13allow them to be very good.

104:15I think we've seen AlphaStar understanding very well

104:19when to take battles and when to not to do that.

104:22Also very good at micromanagement

104:24and moving the units around and so on.

104:27And also very good at producing nonstop and trading off

104:30economy with building units.

104:33But I have not perhaps seen as much

104:36as I would like this idea of the poker idea

104:39that you mentioned, right?

104:40I'm not sure StarCraft or AlphaStar

104:42rather has developed a very deep understanding of what

104:47the opponent is doing and reacting to that

104:50and sort of trying to trick the player to do something else

104:54or that.

104:55So this kind of reasoning, I would like to see more.

104:58So I think purely from a research standpoint,

105:01there's perhaps also quite a few things

105:03to be done there in the domain of StarCraft.

105:06Yeah, in the domain of games, I've

105:08seen some interesting work in even auctions,

105:11manipulating other players, sort of forming a belief state

105:15and just messing with people.

105:17Yeah, it's called theory of mind, I guess.

105:18Theory of mind, yeah.

105:20So it's a fascinating.

105:21Theory of mind on StarCraft is kind of they're

105:24really made for each other.

105:26So that would be very exciting to see those techniques apply

105:29to StarCraft or perhaps StarCraft

105:32driving new techniques, right?

105:33As I said, this is always the tension between the two.

105:36Well, Orel, thank you so much for talking today.

105:38Awesome.

105:39It was great to be here.

105:40Thanks.

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