Leela Chess Zero Refutes The Dutch Defense? | Computer Chess Championship Finals 

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stockfish: "thats not a good strategy!" leela: "strategy? chess is only tactics."

Love Danny’s enthusiasm and why wouldn’t he be so animated. Leela’s play in this game is the stuff of legend.

You really excel at these kinds of videos. Thank you very much!

You didnt explain the horizon effect correctly. The horizon effect is when the computer calculates the position out to a large number of ply and heads down that tree branch only to discover that just beyond where its calculations ended (the horizon) the game is dead lost. For instance a computer calculates 32ply deep and it looks favorable but at the next ply level the position is losing. Kasparov played a great game against deep blue in his first match (game 6) where the computer headed down a branch of the tree that had all dead losses. After a couple of moves the computer then sees the correct eval but it is too late, it had passed the point of no return.

Just a formatting thought: when you are exploring alternate scenarios, have you considered a different coloured board? That might help with differentiating between the actual game and the proposed alternative.

"An abusive Russian chess coach would come along and just sweep those off the board and say something like: You are not using them anyway why you want them? And just throw them away" HAHAHAHA MY F** SIDES

I think Leela "trolls" just to get into simpler positions, Leela knows how to win the queen vs rook endgame and the pawn just complicates things a little bit. Giving up the pawn leads to a simpler game which is still a definite win for Leela.

Danny's analysis of 1. d4 f5 - "maybe it was a mouse slip". 😂😂 Absolute gold.

Leela "trolling" is a result of neural networks in all games. They find the path of least resistance more often than they find the "best" way to solve a problem. this can be seen in nearly every implementation of neural networks. Leela may see getting more pieces of the board as simplifying the position just as we do and in turn, would be easier for her to convert.

15:22 "The queen lives for black at the end of variation like this,,unfortunately THE KING DOES NOT" -SIM Daniel Rensch 2020

That is crazy, one of the most beautiful games I have seen recently. Amazing analysis Danny

8:09 1...f4 Qxb2 2.Rb1 Qf6 3. O-O Goosebumps...

I just wanted to say thank you, Danny, for always inspiring my chess improvement with your insight, energy, and understanding of the game. I also wanted to thank you for kicking my ass so convincingly in a bullet brawl in 2015 that I really hunkered down and decided to start improving my game; after some breaks due to college I finally crossed the 2000 online blitz threshold last month. You’re an inspiration, man!

Next time: Leela Chess Zero refutes 1.e4

Loving the Russian accent danny.

I love the Russian chess coach joke. Seemed so real.

I wish you said when the opening ended and the engine moves started. @9:20 "that you created Stockfish when you moved your f pawn on move one" I think most people who aren't used to computer chess won't understand that Stockfish didn't decide to play f5.

Great video. Your analysis was as evident as your enthusiasm!

I watched this game live and freaked out in the chat with everyone else starting from d6. From d6 it was clear that Leela was just going to crush positionally and not only did she do that, but she also crushed tactically, and taking black's queen was one of the most thrilling moments to watch. We had a party in the chat. Absolutely incredible game! Thank you for the analysis!

This reminds me of AlphaGo playing Go and sometimes instead of grabbing a large advantage, it would instead play something which seems relatively insignificant. This puzzled many humans. The reason was that since you only need to win by 0.5 points to win the game, AlphaGo would go for smaller advantage if it is more confident it would lead to victory instead going for larger advantage, which is not a safer choice (but in the games they would have been incredibly safe nonetheless). A human player would go for a larger advantage to maximize chances to win.

the sac of the queen is because of the Table base. sacking the queen is not the shortest path to mate but it is the shortest path to a winning entry on the tablebase

I haven't seen too many of these instructional videos (involving openings) by Rensch in recent times, but really liked his way of presenting the ideas. However, hope he'll continue make much more of these!

Because the algorithm would only be changed when lost,the " trolling " moves or the unnecessary moves wouldn't be ruled out as long as it's winning, therefore it still plays it

That picture had me laughing so hard, “one does not simply play f4” so well done and all chess players can appreciate that

we really don't know why she "trolls" but it always happens when there are numerous winning lines. If you can imagine that all her knowledge comes from playing against herself, it's possible that in enough games to be significant, perhaps she's managed to stalemate herself which caused her to seek lines that are simplified and might explain why she prefers to sac her pieces for the familiar QvK or RvK endgames. It has also caused her to shuffle in to draws from winning positions though. A future(soon) patch is aimed at solving this hopefully.

8:23 Ben Finegold says to not play f3, not f4. He often uses his "never play f3" adage to illustrate when to play f4. But yeah, f4 is also a weakening move.

Don’t tell Simon Williams!

Great analysis, but that’s totally not why it’s called a “horizon effect”. It’s because you can only see so far ahead before things are hidden below the horizon. No matter how much you understand about what’s close (imminent moves), a depth search like Stockfish’s won’t help with what’s beyond the horizon.

Fucking love Danny he's so funny and charismatic, not to mention a fantastic teacher

Great video, thank you! It was not only entertaining but also very educational.

This is the best game I have seen this year so far. Amazing stuff

Actually, i played this game with Komodo 13.3, and after move 19. Rg4 Komodo shows up black Rf6 as best move for black, but still with big disadvantage (-1.7) for black! So Komodo did it right! If Rf2 instead, Komodo plays: 20. Rxg6 Qe4, 21. Rg3! Qxe2, 22. Qxe2 Rxe2, 23. Bh6 etc. with total demolition (even without Queens!).

great! wanna see more analyses by Dani Rensch

Superb! Thank you for bringing us these amazing games with deep analysis.

I lived in AZ until May of 1999 and began to get back into Chess during that period. Tal Shaked was a young rising star then. He had a Chess Column, which I believe appeared in the Arizona Republic for a time. I imagine you would have been aware of this growing up. I have been enjoying your humor, analysis and instructive approach for several years now. Always fun to watch you and Hess quarrel.

thanks for both the good analysis and humor Daniel!

Not going to lie the only thing better than these games is your commentary, love it haha

8:22 Ben Finegold never disapproved of f4. Pawn to f3 on the other hand…

So much passion in commentary, amazing)) btw much better then agad does in these days

Kingcrusher: Stockfish has 'spectator' pieces

Daniel’s commentary is always, without a doubt, top notch. Even throwing that bit about his boys playing table tennis cracked me up.

Amazing. Please make more of this type of video Danny you’re the man!

Danny is the best commentator ever. I could listen to him talk about about the color brown.

*Bobby Fischer:* e4 is best by te- *Leela:* I just refuted it. *Bobby Fischer:* 😨

Brilliant and intelligent chess commentary and analysis. Great raconteur. Amazing game

Lovely game. Thanks for explaining it. As a fan of the Dutch (Stonewall) and after getting stung by the Staunton Gambit too many times, I now only enter the Dutch by transposition.

A beautiful game indeed. Daniel’s presentation along with teaching and analysis is spectacular. Plenty of effort and time he’s been dedicated for this video. I really loved it and thank you very much for that. Stay safe, stay sane🤪

"She plays with her food..." LMAO

The Mouse slip at 9:23 😂😂

Great dedication to stream the video just after finishing an analysis, Danny!! PS- The last part where you mentioned why would any neural network want the game to last longer than it should will keep me driving all day, motivates me to search more on NN and Machine Learning !!! :-D

00:58 D-man spitting a few quick bars.

What flare. I could listen to this guy all day.

Great stuff! I would like to learn more about Leela trolling with sacrificing pieces that lead to longer mate paths. It seems like Leela is prefering fewer pieces on board and longer mates that more pieces and shorter mates.

Once a game is in a won position, there's no pressure on the neural network to refine its play at all in its learning process. So you'd expect some pretty random moves while in a won position (as long as they don't jeopardize the win).

I absolutely love your commentary.. If you're looking for another game to analyse check out tcec game 35. A classic sicilian dragon with all the standard motifs you would come to expect (opposite casting pawn storms on both wings exchange sac on c3 etc...) played briliantly by both entities... At 5:17 it seems like black might just get away with e6(?)

Endgame tablebases is why Lela played the ending the way she did. She saw that it was forced mate all the way to the end.

Love the screen shot

Leela doesn't troll. It's just that when there are several winning lines she picks the one where she has to do the least amount of calculation. It's just efficiency.

I never thought chess commentary could be so entertaining. Killing it Daniel!

If I had to guess, I would say that Leela "trolls" because reinforcement learning has a reward structure. Leela is probably set up so that it rewards incrementally throughout the game rather than just once right at the end for a win. This is because it makes it faster to train the neural network, though it may not lead to the most optimal results (but those most optimal results may not be practically attainable anyway). Therefore, the neural net probably prioritizes winning most of all, but if it can be winning for the longest number of moves, that's better because it receives a bigger reward. That, or Leela is mainly focused on winning independent of the number of moves it takes. It may just focus on the likelihood of winning for a given position rather than winning in the most precise way.

This is the kind of daniel rensch that i like

Great game! Thank you for the coverage! That 19...Rf2 20. Rxg6! Qe4 21. Rxg7! Kxg7 22. Nf4!! just stuned me! Just wonderful!

Wonderful game and commentary, this has just become one of my alltime favourite Leela games. Thanks Danny.

She’s not trolling. The way neural networks works work in chess are by number of possible moves being computed. By eliminating both of those pieces it makes calculations easier on the network. Just less variations. That’s why Leela will consider promote to a knight first because it has the lease number of variations or moves leading to mate.

Leela's MCTS approach leads 'her' to safer areas of the tree *when Leela can't see a concrete win*. That imo is why you see apparent trolling.

Beautiful game and great analysis. Thank you!

I think the trolling simplification when Leela sacks Q for R is because she sees a 7 piece tablebase win which is a Good Thing. Maybe the pawn discard (it's not even a sac) is for the longest win, yeah, playing with her food.

I Love This guy! very funny and insightful!

awesome video, I love your enthusiasm

Wow, brilliant analysis on a brilliant game!

Tnx for sharing ..i realy enjoy watching it wit analisis

The sales of GM Simon's Rebooted Killer Dutch will be halted.

Thanks for making these videos Danny

incredible play by Leela. So much to discover with this new engine.

16.f5 is a clear oversight by SF due to LMR (late move reduction, i.e. aggressive move pruning algorithm of SF). That is a (rare) example of position where human+engine is much more powerful than engine. It would have been enough for human to run SF in MPV mode and explore a couple of moves in advance, i.e. what would be a typical correspondence player strategy. And it would easily see that just two moves earlier instead of 14. .. Qf5, b5 equalizes by opening the left side and activating those inactive pieces. Also, Kh8 equalizes by removing that weak king position on white square. So, essentially before 14. .. Qf5 blunder of SF position was equal. Since SF has such an aggressive LMR it takes it to reach depth 46 on move 14 before it can actually see that Qf5 is a blunder.

Amazing game, thanks for the great analysis Danny.

.Absolutely love the thumbnail. Oh and Danny you’re the best

If anyone knows the M20 computer vs David Bronstien chess match, you can see that the computer lost as it was taking all of David's pieces. It was programmed in such a way that the more pieces you have, the more chances you have to win. But David takes positional advantage by sacing pieces. And today you see that Lc0 is programmed and learned in such a way that positional advantage is very much more important than some pieces. With this I personally feel that chess would be a really competitive game for the generations to come (when I say competitive, I mean that there is a chance players may have 3200/3300 rating) since there teachers are going to be these present beasts like Lc0. What are your thoughts about this?

OMG! Danny and Leela just blew my mind a dozen times!

Love the commentary

you. are. crazy. good. Please more tournaments with gingergm etc. we all here to watch! Thank you for the crazy content!!!

Great stuff for me!!! I like to play the Staunton and I LOVE(!) Queen vs. Rook, studying that for months(!?!). Thanks a lot!!!

2:00 Queen sac game

Thanks to Danny & Leela Chess Zero, we will no longer be terrorized by the Dutch Defense ever again, now what do we do after 1.d4 f5 again!!?

From the title I'm looking to check for a new theory against the dutch defence. But who's going to play like that? Giving up pawns and even pieces, having your pieces hanging. Undertaking for a line that is looking forward 5 moves ahead making sure that is rock solid from every point of view. This is too scary for any human. Can't learn too much from that apart having enjoied a beautiful looking game.

Great video Danny, cheers!

Thank you Danny 💗

Good stuff. Anyone else wanna see Seirawan chess, S-Chess, SHARPER or whatevs with the engines going at it? It would be great to just have it available online somewhere, as the two extra pieces of dynamism should have at least us and probably also the neural networks busy for quite a while with all the new possible complications available.

stylish game and great pragmatical explanations

These are my favourite kind of videos :D Danny the best

Great analysis and great enthusiasm = great video!

Why not pause the video for a few minutes and see if you can spot Leela's continuation... 🙂

A great game... and a great presentation! Many thanks.

For the crazy endgames I believe that (btw I really believe that...) the engineers made leela look for the hardest way to finish an endgame, so that it can not only destroy Stockfish in fashion but also teach us and educate us even more on those crazy endgames where you are up a queen against a rook. So I think Danny is correct. There could be another technical reasons... Maybe Lc0 the way the code is written is just easier for her to look for those book endgames rather than discovering them herself, but either way we are having a good lesson out of these positions for sure!

All of this just because fxe4 What a weapon

I think the reason leela made that bizarre queen sacrifice at the end is that she, like most chess engines, has memorized all endgames involving 6 pieces, and so she knew that if she sacrificed the queen, she could win without having to think, wheras if she pushed the pawns, she'd have to think for a bit longer. You ask "why make the game take longer than it needs to?" but actually for her, it makes the game shorter, in terms of milliseconds on her chess clock.

Great video Danny!

So called Leela Troll Moves: 72. a7 instead of h5 75. Qf8 instead of g4 81. Qc1 instead of Qc2+ 85. Qxb6 instead of g6! (85. g6 Rb1 86. Qxb6 wins a tempo) 101. d7 instead of Qf6 (converting a mate in 11 to a mate in 28)

Leela sacrifices whatever pieces if she's still able to win regardless, that's the entire playstyle, it's not trolling it's genius. She didn't need them, it's like she's eliminating dead weight, and to an extent if your opponent has a lot of pieces on the board it makes it less easy for him to develop.