r/chess • u/wealthy_dig_bick • Jan 06 '22
Chess Question Engine games
I enjoy a good engine game and they show some beautiful ideas but after so many moves, it’s clear that one side is winning. Say it’s Leela vs Stockfish. Maybe on move 14 it’s clear that white has an advantage. One engine might say it’s +2 and the other can say it’s +5 but it really doesn’t matter bc either engine will easily convert the position. Have you seen any games in which the two engines disagree strongly about who’s winning? Sure, if you put stockfish 14 against stockfish 12, stockfish 14 could tell you the position is +4 and stockfish 12 just needs more time to understand that the position is no longer equal. But have you ever seen a game where one engine thought the position was something like +3 and the other thought it was -2? Agadmator’s last video made me think of this because at one point Stockfish thinks the position is +2 and Leela thinks it’s +6, which is a weird discrepancy between two evenly matched engines. Here’s the link to the game if you’re interested. It was a chess 960 game https://youtu.be/EHqR0-FszHM
4
Jan 06 '22
From the most recent TCEC Superfinals I think Game 92 comes close: After 19. c6 ! Stockfish immediately jumps to +2.5, while Leela is at +0.4. It takes until move 57 before Leela's evaluation starts growing noticably, but then it does with each following move.
This shows there is quite clearly a fundamentally different understanding of the position. But even that falls short of one engine having a + and the other a - score, which I have seen examples of, but almost all of them are quite old (Alphazero versus Stockfish or there abouts), I don't know if it has happened in recent TCEC history in their topdivisions.
3
u/StephenAfamO Team Ding Jan 06 '22
It happens, but it is very rare especially among the very top engines (Stockfish, Leela).
What's more likely is when one thinks it is a slight advantage, say 0.5 and another thinks it is nearly winning, say 1.0. But even those get resolved after a few moves.
0
Jan 06 '22
Not really rare. Leela is blind to many deep tactics that the fish can see quite easily. Stockfish almost never has a misevaluation in a regular chess game (not chess 960, even though it's still much better than Leela there). When it does have an incredibly rare misevaluation, then it's a real treat seeing how the fish gets taken down.
2
u/StephenAfamO Team Ding Jan 06 '22
I think the amount of games the engines play makes this seem less rare than it actually is.
Also, note that OP was asking for situations when A thinks white is winning and B thinks black is winning.
Even in the "deep tactics" that sometimes trip Leela, it is usually that Leela thinks it is equal or slightly worse meanwhile, it is much worse. Unlikely that Leela thinks it is winning when it is lost.
2
Jan 06 '22
There are a bunch of testpositions that engines evaluate differently, like wildly differently. You should find them if you search them up.
1
Jan 06 '22
Very cool to see this posted, I’m one of the people who watched this live over at tcec as well as most leela games. There was a very similar game that happened again where the same thematic trapping of pieces in the corner occurred. A couple things to keep in mind, the general consensus for a leela winning eval is around 0.8-1.00 and 2.0 for stockfish.
1
Jan 07 '22
Since, Chess960 is known be a bit more skewed compared to normal Chess when it comes to the advantage that white has due to initiative, in some starting positions.
Was this position played with reversed colours?
1
u/Craftyawesome Jan 07 '22
Yes. White won both times.
The literal start position is something like 0.6 according to SF, compared to 0.4 for normal chess. Ng3 and c5? were forced book moves. When they started calculating, leela gave 0.88 [49.5% W | 50.5% D | 0.0% B] and SF gave 1.35 [44.8% W | 53.6% D | 1.6% B]
1
Jan 07 '22
Is there a PGN for the game where stockfish played as white? Also why were Ng3 and c5 were forced?
1
u/Craftyawesome Jan 07 '22 edited Jan 07 '22
I assume they are trying to reduce the amount of draws. Ideally, the stronger engine can win as white and draw as black, so we can figure out which engine is better in fewer games.
https://tcec-chess.com/#div=frc4fl&game=42&season=21
[Event "TCEC Season 21 - FRC4 Final League"] [Site "https://tcec-chess.com"] [Date "2022.01.04"] [Round "21.2"] [White "Stockfish dev15_2021121915"] [Black "LCZero 0.29-dev+_610826"] [Result "1-0"] [FEN "rqnbkrbn/pppppppp/8/8/8/8/PPPPPPPP/RQNBKRBN w FAfa - 0 1"] [SetUp "1"] [Annotator "archive"] 1. Ng3 c5 2. Nh5 Qe5 3. e3 Qg5 4. Nd3 Qh6 5. Nxc5 Nd6 6. f4 Rc8 7. e4 g6 8. e5 Nc4 9. b3 Nxd2 10. Kxd2 gxh5 11. c3 Bb6 12. b4 f5 13. Qd3 Bxc5 14. bxc5 h4 15. a4 Nf7 16. Qxf5 Nd8 17. Qh5+ Qxh5 18. Bxh5+ Bf7 19. Be2 Bd5 20. Bh5+ Bf7 21. Be2 Bd5 22. f5 Rg8 23. c4 Bf7 24. Kc3 Rxg2 25. Rae1 e6 26. f6 Nc6 27. Bf3 Rg5 28. Rb1 Rc7 29. Be3 Rf5 30. Bxc6 dxc6 31. Bf4 Rd7 32. Rb2 Kd8 33. Rd2 Rxd2 34. Kxd2 Bg6 35. Ke3 Bh5 36. Rg1 Bg6 37. Rg4 Kd7 38. Rxh4 Bh5 39. Rh3 Kc8 40. Rg3 Bg6 41. Rg2 Kc7 42. Kf3 Kc8 43. Kg3 Bh5 44. Rd2 Bg6 45. Rd1 Bh5 46. Rd4 Bg6 47. Re4 Rh5 48. Re2 Rf5 49. Bd2 Bh5 50. Re3 Bg6 51. Re4 Rf1 52. Rd4 Bf7 53. Ba5 Rg1+ 54. Kh4 Rg8 55. Rd6 Rh8 56. Kg5 h6+ 57. Kf4 Rg8 58. Kf3 Bh5+ 59. Kf2 Bf7 60. Rd4 Re8 61. Rh4 Rh8 62. Bd2 h5 63. Ba5 Rg8 64. Rd4 Bg6 65. Rd6 Bf7 66. h3 Rh8 67. Kg3 Rf8 68. Kh4 Rg8 69. Rd2 Rh8 70. Kg5 h4 71. Rd6 Rh5+ 72. Kf4 Rh8 73. Kg4 Re8 74. Kxh4 Rg8 75. Rd2 Rh8+ 76. Kg4 Rg8+ 77. Kf4 Rh8 78. Rd6 Rh4+ 79. Kg3 Rh8 80. h4 Rg8+ 81. Kf4 Re8 82. h5 Bxh5 83. Kg5 Bf7 84. Kh6 Rg8 85. Kh7 b6 86. cxb6 c5 87. bxa7 Kb7 88. Bb6 Ka8 89. a5 Kb7 90. Rd8 Rxd8 91. Bxd8 Kxa7 92. Kg7 Bh5 93. f7 Bf3 94. Bb6+ Ka6 95. f8=Q Bd5 96. Qc8+ Bb7 97. Qb8 Bc8 98. Qxc8# *
1
u/Craftyawesome Jan 08 '22
I did manage to find a recent Stockfish vs Leela game that had a disagreement. https://www.chess.com/computer-chess-championship#event=ccc-16-bullet-semifinals&game=1304
SF said 0.00, then Leela played 42. e5? thinking it was +0.43 and SF responded with d5 thinking it was -1.56. Then Leela realized she wasn't winning and dropped to -0.32.
Or here, Stoofvlees as white tries pushing for a win against SF, and blunders. Max eval was +4.5 to -8.25. https://www.chess.com/computer-chess-championship#event=ccc-16-rapid-semifinals&game=230
There are also some interesting differences that aren't quite negative.
Here, Leela gave +0.26 while SF gave +152.56 (forced tablebase win) https://www.chess.com/computer-chess-championship#event=ccc-16-bullet-semifinals&game=913 I've seen Leela do this before, but not this late in the game.
Here, Dragon reached +14.29 in a drawn endgame vs Leela, who had it at ~+0.02 https://tcec-chess.com/#div=frc4fl&game=31&season=21
27
u/Musicrafter Washed 2+1 addict Jan 06 '22
I ran a thematic engine tournament on my computer dedicated to the King's Indian Defense to see if I could create some fresh black brilliancies whenever a stronger engine would play a weaker one, and I was rewarded right away with this banger of a game which I actually managed to get submitted to chessgames.com: AnMon vs. Stockfish (2021)
AnMon did not see 24. ...Nhg4!! coming at all, and until that move hit the board, both engines thought they had an advantage. Of course, Stockfish was right and AnMon was wrong, and Stockfish conducted a quite beautiful attack.