This is a transcript of a recorded chess session and conversation between Lex Fridman and Demis Hassabis (five-minute blitz game). They discuss move-by-move play, openings (English), middlegame/endgame strategy, time pressure, and AlphaZero's stylistic innovations (notably sacrificial play and an "immortal Zugzwang" game vs Stockfish). They also discuss the chess book Game Changer by Natasha Regan and Matthew Sadler, which documents AlphaZero’s ideas and includes behind-the-scenes material.
Questions this video answers
Five minutes per player (blitz).
Natasha Regan and Matthew Sadler.
White (Lex says "You've given me white, Lex," indicating Demis had white).
Chapters
You probably need to have multiple agents running in your head. So one agent is, how do I play? Good chess?
Yeah.
Second agent, how do I play? Not too good of chess. And third agent is, how do I help Lex move?
Correctly. Correctly, sure. Okay, we have five minutes each. Looks like I've got. You've given me white, Lex, which is nice of you. We will start the clock. So my clock's counting down? Yes. Okay.
Non standard.
Yeah, the English opening. You know, I'm English, so I have to do that. So, you know, you press the clock when you're. When you've done your move. That's a good starting move. Very solid, Lex.
Oh, that's not a good.
No, this is good. This is very solid.
Okay.
We're quite far away from the. From the board.
Oh, yeah, yeah.
I'll press your club for you. Don't worry. All right.
Are we far away from the English opening at this.
No, this is a. This is a good line. You're playing very, very standard.
You have to get used. They always do the funny thing where.
Very nice hitting me.
You have to take notes of actually what move you're. You've taken.
Yes. Yeah, that's a good. Always a good plan. Keeping the king safe. I'm gonna do the same. Played very well so far.
Would you. Would you say. Any major mistakes at this point?
Nothing so far.
I'm not gonna.
Oh, here's the bishop knight swap that we were talking about earlier. Right? The tension. You're creating the tension in the creator, Tension in the game.
The tension.
Relieving the tension. Exactly.
All right.
Now it gets harder. Now you have to come up with your middle game plan.
Would you say.
You did a very good opening. So you're in a. You're in a. You're in a fine position so far. Yeah, very nice. Very nice.
What's your strongest opener? Opening game or end game?
I would say probably the middle game. Middle game. So this kind of. This kind of point. Very good. Very good. Very aggressive. Very aggressive legs.
If I could. If I could sacrifice pieces, I really would. That's not a good move, is it?
No, that's a good move. That's a very nice move.
Are you afraid of using the queen?
Yeah, the queen. You know, you've got to be careful when you use the queen. I need to complicate the game a little bit for you. You're doing too well, Lex.
Oh, am I losing a piece here?
No, you're not losing a piece. You're doing okay, actually. I'm gonna take it anyway. Only a pawn.
That's how it starts.
That's how it starts. But it's only a pawn. Very good. Still a pawn. Only a pawn.
Sorry, I have to. I don't feel comfortable with you having a queen on the board.
Take the queens off. Less dangerous.
Makes me feel more safe.
Yeah. So now we're in the end game now. So you're. You're in better territory.
What's the definition of an end game?
Well, the queen's coming off is you. Usually the beginning of the end game. It's not the only part of the end game, but it's. It's one bit of the end game. See, that's a pretty cool idea, what you've done there. I'll take off your knight now.
I think the Internet's gonna disagree with that.
Now I'm. You see, this is an interesting dynamic position with your bishop and my knight. But my. My knight's in a good, good strong spot there.
Ah, so you're attacking the bishop. My. My own. The bishop is not. So what do I do with this bishop?
Yeah, what are you.
Maybe I need some other kind of way.
All right, yeah, maybe.
But then you're going to attack there. I don't know. I think I'm just running scared.
Running scared now here.
Can't run your moon.
Run it.
Okay. Yeah, that's not. Is that.
That's the only move?
Actually, this the only one. All right. It feels like there's not much to do here.
Well, you've gotta. You have to. Have to come at something good here.
Oh, boy. And the time's running out.
And time's running out. Escape. That's a good escape for your king. I'm gonna come here now.
Yeah. There's nothing else. There's nothing else.
Take another. Get another one of your pawns.
I feel like there's some smart move that I'm totally missing.
Yeah, that seems reasonable. But not going to take a second pawn. Okay.
That's what you mean.
Yeah. I'm gonna go here.
They could just eat away at the.
Eat away at your stuff. All right. Yeah.
This is not.
This is slowly, slowly constricting you. Slowly going to take all your pawns. You play very well, though, Lex. You haven't made any major mistakes. It's just slow, slow, slow death.
The Internet honestly will very much disagree. But let's see this. A slow death is better than.
Than a. Than a fast death.
Embarrassing in the beginning. I didn't get checkmate in the first few moves. This feels very constraining.
Slowly constrained I feel like alpha zero.
Is it that?
Yeah, kind of controlled. Controlled end.
You know, the interesting thing is the willingness to sacrifice pieces by alpha zero. That's so beautiful.
It is beautiful. See? So now I'm going to make use of all these pawns I've taken.
Would you say your alphazero is much better than us sacrificing pieces?
Oh, yeah. Intentionally. I sometimes, you know, lose them by mistake, but Alphazero is planning to lose them.
This feels extremely constraining.
Yeah.
How close are you? Checkmate. Is there any way for me out of this?
Not really, no.
So these pieces can't.
Yeah, I'm getting. Basically all your pieces are getting constrained. I'm just going to march these pawns down here or bring this rook to help out.
Okay. So if I take this knight with the rook.
Yeah, you could do that. That would be a final sort of hope. My knight's. You see how strong my knight's been in this game compared to your bishop? Yeah. As we were talking earlier. Yeah. It's done all the damage. Yeah. You can get rid of him now, but I think he's already. It's already.
Oh, and my time ran out.
And your time run out.
We're gonna finish the game.
Finish the game anyway. It's time right now. So you've lost once, but we can. We can lose two times. Yeah, take that. But now I'm gonna get. Take advantage of your back rank weakness. All right. And right.
And then this pawn structure. You're gonna bring out the other.
Yeah, I'm gonna bring the other. Finally going to swing the other rook into the game. Check. And I'm just gonna keep running.
How many moves would you estimate here?
It's gonna be about 10. For here, I'm going to swap your rook off. Your final defensive piece. I'm going to take.
Is that.
No, that's. That's fine. Well, you can. I'll check you here.
Oh, yeah. And you just march that.
Yeah. Going to march this pawn to the end now.
Well, I think this is a good.
You played well.
Honor to have been defeated so gracefully.
You played very, very well. I was impressed. I was impressed. You. You did. You did great.
I didn't ask you. What do you think is the most beautiful thing you've seen Alphazero do?
Yes. So there was actually the most beautiful game that I've seen AlphaZero play is being dubbed the immortal Zugswang game by Acadamata on the one of YouTube. Brilliant YouTube commentators. And he. It was AlphaZero playing stockfish and sacrificing a load of pieces to get Stockfish's. All of the Stockfish's major pieces, queen and two rooks stuck in the corner, basically sealed them up like in a tomb. And Zugzwang means that any move that the player makes will make their position worse. And it's never been done to Stockfish before. And Alphazero did it super elegantly through sacrificing pieces. Sacrificing pieces, yeah. It's a beautiful video online on it.
And thank you for giving me and signing this book. Game changer.
Welcome. You're welcome.
What is the book about?
The book was written by the British chess champion and women international master, Natasha Reagan and Matthew Sadler. And I known them both for years, from my chess days as I was a kid. And when they heard about AlphaZero before we released it, they wanted to come in and try it out. And we gave them full behind the scenes access to it. And then Matthew Sadler said to me, it's like discovering the notebooks of of a hidden champion that no one knew about. And he then wrote this book about all of the different ideas that AlphaZero had. And the cool thing is in there in that book. So it's a chess book, but also the first few chapters about how we built Alphazero, our journey towards it. And then Magnus Carlsen was one of the first people we gave the book to and he sort of publicly said it was very useful to him. And he's incorporated a lot of the ideas into his own play.
The new ideas, you could say, Created by AlphaZero.
AlphaZero.
To Lex, a fellow explorer of the mysteries of the universe. Demis, thank you so much. Thank you for everything you do.
