Difficult game variant for Stockfish 16!

[Eduard]

Difficult game variant for Stockfish 16!

The following game was played today on PlayChess:

[pgn][Event "5 min, rated"] [Site "Engine Room"] [Date "2023.08.02"] [Round "?"] [White "Big_pat-82, Dragon 3.2 by Chess.com"] [Black "Python, Lc0 v0.31.0-dag+git"] [Result "0-1"] [ECO "D30"] [WhiteElo "3174"] [BlackElo "3176"] [Annotator "0.00;-0.68"] [PlyCount "194"] [EventDate "2023.08.02"] [EventType "blitz"] [TimeControl "300"] 1. Nf3 {B 0} d5 {B 0} 2. d4 {B 0} Nf6 {B 0} 3. c4 {B 0} c6 {B 0} 4. e3 {B 0} e6 {B 0} 5. b3 {B 0} c5 {B 0} 6. Bb2 {B 0} cxd4 {B 0} 7. Nxd4 {B 0} e5 {B 0} 8. Nf3 {B 0} Nc6 {B 0} 9. Nbd2 {B 0} d4 {B 0} 10. exd4 {B 0} e4 {B 0} 11. Qe2 {B 0} Bf5 {B 0} 12. O-O-O {B 0} Qa5 {B 0} 13. Nh4 {0.00/25 7} Bg4 {B 0} 14. f3 {0.00/33 7} O-O-O {B 0} 15. d5 {0.00/34 6} (15. Nxe4) 15... Nb4 {B 0} 16. Bxf6 {0.00/36 6} gxf6 {B 0} 17. Nxe4 {0.00/39 10} Bd7 {B 0} 18. Kb1 {0.00/40 6} f5 {B 0} 19. Nf6 {0.00/41 40} Bg7 {B 0} 20. Nxd7 {0.00/43 7} Rhe8 {B 0} 21. Qd2 {0.00/45 7} Re3 {B 0} 22. Nc5 {0.00/44 11} Bc3 {B 0} 23. Qf2 {-0.29/44 41} Bd4 {B 0} 24. Qd2 {-1.43/28 4} Bxc5 {B 0} 25. Nxf5 {-1.73/28 3} Rde8 {B 0} 26. d6 {-1.57/31 4} R8e5 {-0.68/25 56} 27. Ne7+ {-1.74/39 0} Kb8 {-1.33/25 8} 28. d7 {-1.84/33 0} Qd8 {-1.46/23 8} 29. Nd5 {-1.77/36 0} Rxd5 {-1.53/23 8} 30. cxd5 {-1.78/37 0} Qxd7 {-1.59/21 8} 31. g4 {-1.78/33 0} Qd6 {-1.56/20 8} 32. h4 {-1.80/33 0 (Lc4)} Qg6+ {-1.58/19 8} 33. Bd3 {-1.87/33 0} Nxd3 {-1.57/18 7} 34. h5 {-1.88/34 0} Qb6 {-1.65/17 7} 35. Rh2 {-1.91/33 0 (d6)} Ne5 {-1.82/16 7} 36. Qb2 {-1.90/32 0} a6 {-1.75/17 7} 37. Rc2 {-1.97/33 0} Ka7 {-1.70/17 7} 38. d6 {-2.01/31 0} Bxd6 {-1.62/16 6} 39. Rc3 {-2.09/30 0} Ba3 {-1.58/15 6} 40. Qd2 {-2.14/31 0} Rxc3 {-1.55/14 6} 41. Qxc3 {-2.09/31 0} Nc6 {-1.53/13 6} 42. Qe1 {-2.27/30 0} Bb4 {-1.52/11 6} 43. Qe2 {-2.28/30 3} Bc5 {-1.54/10 5} 44. Rd7 {-2.37/29 0 (Dc4)} Be3 {-1.57/10 5 (Ba3)} 45. Rd1 {-2.10/29 9} Bg5 {-1.56/11 5 (Bd4)} 46. Qd3 {-2.18/30 6} h6 {-1.52/12 5 (Bf6)} 47. Qc3 {-2.09/26 6} a5 {-1.54/12 5} 48. Qd3 {-2.30/28 0 (Dc2)} Bf6 {-1.72/11 5} 49. Re1 {-2.53/27 3 (Dd6)} Qc5 {-1.78/11 4} 50. Qe3 {-2.93/28 5} Bd4 {-1.76/13 4} 51. Qd3 {-2.77/31 0 (Dc1)} Qg5 {-1.92/11 4} 52. Re4 {-3.25/27 2 (a3)} Bb6 {-2.50/11 4} 53. Rc4 {-3.30/25 0} Qe7 {-2.52/10 3} 54. Rc1 {-3.52/27 5} Nd4 {-2.37/10 3} 55. Rd1 {-3.80/27 2} f6 {-2.63/10 3 (Qe5)} 56. Rc1 {-3.85/26 6} Qd6 {-2.88/11 3} 57. Re1 {-4.01/28 7 (Tc4)} Qh2 {-2.96/11 3 (Qg3)} 58. Rd1 {-4.21/26 3} f5 {-3.66/11 3 (Qg2)} 59. gxf5 {-4.09/22 3} Qxh5 {-4.26/10 2} 60. a3 {-4.39/22 2 (De4)} Qf7 {-5.27/9 3} 61. f4 {-4.98/22 2 (b4)} h5 {-6.94/9 2} 62. f6 {-5.58/22 3 (b4)} Qxf6 {-8.69/8 2} 63. a4 {-6.28/21 5 (f5)} Qxf4 {-36.31/7 2} 64. Rc1 {-8.03/19 4 (b4)} Nc6 {-16.07/7 2} 65. Rc4 {-9.54/20 0 (Txc6)} Bd4 {-29.56/7 2 (Qe5)} 66. Qd1 {-11.75/21 3 (b4)} h4 {-22.58/7 2} 67. Qd3 {-14.11/21 1} Qg4 {-18.43/8 1 (Qe5)} 68. Qd2 {-16.69/20 3} h3 {-13.85/8 1 (Qe4+)} 69. Rxc6 {-17.47/20 1} bxc6 {-19.65/10 1} 70. Qxa5+ {-250.00/25 0} Kb7 {-15.25/10 1} 71. Qb4+ {-250.00/31 0} Kc7 {-16.94/9 1} 72. Qe7+ {-250.00/30 0} Qd7 {-26.07/8 1} 73. Qe4 {-250.00/29 0} h2 {-36.83/7 1} 74. Ka2 {-250.00/29 0 (Df4+)} Bf6 {-58.14/6 1 (Bc3)} 75. Qf4+ {-#11/23 0} Qd6 {-27.40/8 1} 76. Qf2 {-#9/24 0} Kb7 {-47.12/7 1} 77. a5 {-#8/26 0} c5 {-49.48/7 1 (h1Q)} 78. Qe1 {-#10/20 0 (Dg2+)} Qd5 {-78.39/6 1 (Qc6)} 79. Qe2 {-#8/21 0 (a6+)} c4 {-35.49/8 1 (h1Q)} 80. a6+ {-250.00/22 0} Kxa6 {-104.19/7 1} 81. Qxh2 {-250.00/27 0 (b4)} Qa5+ {-#110/2 1} 82. Kb1 {-250.00/30 0} Qa1+ {-#109/2 1} 83. Kc2 {-250.00/30 0} Qb2+ {-#108/2 1} 84. Kd1 {-250.00/31 0} Qxh2 {-#107/2 1} 85. bxc4 {-250.00/99 0 (Ke1)} Qa2 {-1/0 0 (Qb2)} 86. Ke1 {-#4/20 0} Qxc4 {-4/1 0 (Qg2)} 87. Kf2 {-#5/17 0} Qd3 {-3/0 0 (Qe4)} 88. Kg2 {-#5/18 0} Qe2+ {-2/1 0 (Qe3)} 89. Kg3 {-#4/21 0} Bg5 {-1/1 0} 90. Kh3 {-#3/25 0} Bh4 {-1/1 0 (Bf4)} 91. Kxh4 {-#1000/5 0} Qg2 {-6/1 0 (Kb5)} 92. Kh5 {-#13/5 0} Kb5 {-5/0 0 (Qg7)} 93. Kh6 {-#7/20 1} Kc4 {-4/0 0 (Qg8)} 94. Kh7 {-#4/20 0} Kd4 {-3/0 0 (Kd5)} 95. Kh6 {-#3/69 9} Ke5 {-2/1 0} 96. Kh5 {-#2/69 0} Kf5 {-1/1 0} 97. Kh4 {-#1/66 0} Qh2# {-1/0 0 (Lag: Av=0.42s, max=0.8s)} 0-1[/pgn]

Black played with Lc0 and my Lc0 tournament book. Lc0 won by a book killer variant! At first I thought that only Dragon 3.2 had problems with the variant, but that's not true. Stockfish 16 is blinder than Dragon 3.2!

The killer variant starts at move 19. Black is in the book until move 25, after which Black's position is won.

Here are some analyzes with Stockfish 16, I'm clicking through the game move by move:
[d]2kr3r/pp1b1pbp/5N2/q2P1p2/1nP4N/1P3P2/P3Q1PP/1K1R1B1R w - - 0 1
Analysis by Stockfish 160723:

20.Nxd7 Rhe8 21.Qd2 Re3 22.Nc5 Bc3 23.Qf2 Bd4 24.Qd2 Bc3
= (0.00) Depth: 42/11 00:00:02 10023kN
The position is equal

2krr3/pp1N1pbp/8/q2P1p2/1nP4N/1P3P2/P3Q1PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

21.Qd2 Re3 22.Nc5 Bc3 23.Qf2 Bd4 24.Qd2 Bc3
= (0.00) Depth: 42/9 00:00:01 5360kN
The position is equal

2kr4/pp1N1pbp/8/q2P1p2/1nP4N/1P2rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

22.Nc5 Bc3 23.Qf2 Bd4 24.Qd2 Bxc5 25.Nxf5 Rde8 26.d6 R8e5 27.Ne7+ Kd8 28.Nd5 Rxd5 29.cxd5 Bd4 30.Bc4 b5 31.a4 bxc4 32.Qxd4 Rxb3+ 33.Kc1 Rc3+ 34.Kb1
= (0.00) Depth: 32/44 00:00:00 3133kN, tb=5
The position is equal

2kr4/pp1N1pbp/8/q2P1p2/1nP4N/1P2rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

22.Nc5 Bc3 23.Qf2 Bd4 24.Qd2 Bc3
= (0.00) Depth: 42/7 00:00:03 14774kN
The position is equal

2kr4/pp3p1p/8/q1NP1p2/1nP4N/1Pb1rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

23.Qf2 Bd4 24.Qd2 Bc3 25.Qf2
= (0.00) Depth: 45/5 00:00:02 9047kN
The position is equal

2kr4/pp3p1p/8/q1NP1p2/1nPb3N/1P2rP2/P4QPP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

24.Qd2 Bc3 25.Qf2 Bd4 26.Qd2
= (0.00) Depth: 46/5 00:00:02 13303kN, tb=3
The position is equal

2kr4/pp3p1p/8/q1bP1p2/1nP4N/1P2rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

25.Nxf5 Rde8 26.d6 R8e5 27.Ne7+ Kd8 28.Nd5 Rxd5 29.cxd5 Bd4 30.Bc4 b5 31.a4 bxc4 32.Qxd4 Rxb3+ 33.Kc1 Rc3+ 34.Kb1 Rb3+
= (0.00) Depth: 38/44 00:00:06 35127kN, tb=2260
The position is equal

Here Dragon 3.2 sees -1.73 against itself! And Stockfish 16? Still totally blind!

2k1r3/pp3p1p/8/q1bP1N2/1nP5/1P2rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

26.d6 R8e5 27.Ne7+ Kd8 28.Nd5 Rxd5 29.cxd5 Bd4 30.Bc4 b5 31.a4 bxc4 32.Qxd4 Rxb3+ 33.Kc1 Rc3+ 34.Kb1 Rb3+
= (0.00) Depth: 41/19 00:00:05 28198kN, tb=1743
The position is equal

2k5/pp3p1p/3P4/q1b1rN2/1nP5/1P2rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

27.Ne7+ Kd8 28.Nd5 Rxd5 29.cxd5 Bd4 30.Bc4 b5 31.a4 bxc4 32.Qxd4 Rxb3+ 33.Kc1 Nxd5 34.Qh4+ f6 35.Rxd5 Rc3+ 36.Kd2 Rd3+ 37.Ke2 Qd2+ 38.Kf1 Rxd5 39.Qxf6+ Kc8 40.Qf7 Rxd6 41.Qxc4+ Kb7 42.Qf7+ Kb6 43.Qb3+ Kc6 44.Qc4+
= (0.00) Depth: 42/36 00:00:03 20895kN, tb=5820
The position is equal

1k6/pp2Np1p/3P4/q1b1r3/1nP5/1P2rP2/P2Q2PP/1K1R1B1R w - - 0 1

Analysis by Stockfish 160723:

28.d7 Qd8 29.Nd5 Rxd5 30.cxd5 Qxd7 31.g4 Qd6 32.h4 Qg6+ 33.Bd3 Nxd3 34.h5 Qb6 35.d6 Bxd6 36.Qc3 Be5 37.Qc4 Nc5 38.Qxf7 a6 39.Rhe1 Nd3 40.Rxe3 Qxe3 41.Qc4 Qf2 42.Qc2 Qd4 43.Qd2 a5 44.a3 a4 45.f4 Bg7 46.b4 Bh8
-/+ (-1.48 --) Depth: 29/64 00:00:10 53899kN, tb=321
Black is clearly better

Only now Stockfish starts to see something! Test it yourself! Stockfish 16 as a blind fish, from move 20 to 27 eval 0.00!

[Ajedrecista]

Hello Eduard:

I tested myself with SF 16 (default net) and the first position (20.- Nxd7) was evaluated as 0.00 up to depth 53, when I stopped the analysis, cleared the hash and restarted the engine.

The search on the second position (21.- Qd2 or 21.- Qf2) was successful and SF 16 started to see something serious at depth 41:

Code: Select all

FEN: 2krr3/pp1N1pbp/8/q2P1p2/1nP4N/1P3P2/P3Q1PP/1K1R1B1R w - - 1 21

Stockfish_16-windows-x86-64-modern:
Found 145 tablebases
NNUE evaluation using nn-5af11540bbfe.nnue enabled
[...]
 39/10	00:07	   8.074.346	1.083.368	 0,00	Qe2d2 Re8e3 Nd7c5 Bg7c3 Qd2f2 Bc3d4 Qf2d2
 40/26-	00:11	  11.487.463	1.011.843	-0,03	Qe2d2 Re8e3
 40/28-	00:13	  13.646.480	989.233	-0,06	Qe2d2 Re8e3
 40/39+	00:15	  15.371.788	981.721	-0,03	Qe2d2
 40/42	00:22	  21.028.188	957.436	 0,00	Qe2d2 Re8e3 Nd7c5 Bg7c3 Qd2f2 Bc3d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8d8 Ne7d5 Re5xd5 c4xd5 Bc5d4 Bf1c4 b7b5 a2a4 b5xc4 Qd2xd4 Re3xb3+ Kb1c1 Qa5xa4 Qd4h4+ f7f6 Qh4xf6+ Kd8c8 d6d7+ Kc8xd7 Qf6f7+ Kd7d8 Qf7f8+ Kd8c7 Qf8e7+ Kc7c8 Qe7f8+
 41/45-	00:31	  28.716.324	928.129	-0,04	Qe2d2 Re8e3
 41/45-	00:34	  31.398.510	924.655	-0,07	Qe2d2 Re8e3
 41/65-	01:56	 100.769.360	862.492	-1,05	Qe2d2 Re8e3
 41/65	03:02	 153.724.396	842.279	-1,32	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 g2g3 Kc8b8 d5d6 Re3xf3 g3g4 Rf3f2 d6d7 Re8d8 Bf1e2 Qa5a3 Nf5g3 Bc5d4 Rh1f1 Rf2xf1 Rd1xf1 Rd8xd7 Be2f3 Bd4h8 Bf3d5 Nb4xd5 c4xd5 Rd7xd5 Qd2e2 Rd5d8 Ng3e4 Qa3e7 Ne4c3 Qe7d6 Nc3b5 Qd6g6+ Rf1f5
 42/55-	03:21	 169.340.498	840.336	-1,25	Qe2f2 Re8e3
 42/66-	03:24	 171.328.902	840.399	-1,30	Qe2f2 Re8e3
 42/66-	03:54	 196.468.660	837.287	-1,48	Qe2f2 Re8e3
 42/66+	04:09	 207.991.494	834.118	-1,39	Qe2f2
 42/72-	04:55	 246.193.341	832.524	-1,61	Qe2f2 Re8e3
 42/72	05:36	 279.087.462	830.921	-1,69	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 Rh1h2 Nd3e5 Qd2c1 Bc5d6 Rh2c2 a7a6 Rc2c3 Re3e2 Rc3c2 Re2f2 Rc2xf2 Qb6xf2 Qc1h6 Bd6a3 Qh6d2 Qf2xf3 d5d6 Qf3e4+ Kb1a1 Ne5d7 g4g5 Qe4e5+ Ka1b1 Qe5f5+ Qd2c2 Qf5f3 b3b4 Ba3xb4 h5h6
 43/66+	05:50	 291.469.319	831.337	-1,56	Qe2f2
 43/71+	06:04	 303.211.198	831.852	-1,47	Qe2f2
 43/75	06:16	 312.491.021	831.245	-1,56	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 Rh1h2 Nd3e5 Qd2b2 a7a6 Rh2c2 Kb8a7 d5d6 Bc5xd6 Rc2c3 Bd6a3 Qb2d2 Re3xc3 Qd2xc3 Ne5c6 Qc3e1 Ba3b4 Qe1g1 Bb4c5 Qg1h2 Nc6d4 Rd1d3 Qb6f6 Qh2b2 Qf6f4 Qb2c1 Qf4d6 a2a3 Bc5b6 Qc1d2 Qd6f6 Qd2c3 Qf6e5 b3b4 Qe5h2 Qc3d2 Nd4e2 Kb1a2 Qh2e5
 44/75-	06:51	 341.774.003	830.132	-1,62	Qe2f2 Bg7d4
 44/75	07:01	 349.613.532	829.856	-1,60	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 Rh1h2 Nd3e5 Qd2b2 a7a6 Rh2c2 Kb8a7 d5d6 Bc5xd6 Rc2c3 Bd6a3 Qb2d2 Re3xc3 Qd2xc3 Ne5c6 Qc3d2 Qb6c5 f3f4 Qc5b6 Qd2e1 Ka7a8 Qe1e2 Qb6c7 Qe2d2 Qc7c8 Qd2d7 Qc8h8 Qd7d2 Qh8f6 Rd1e1 Qf6h4 Re1e8+ Ka8a7 Qd2e3+ b7b6
 45/70	07:26	 370.054.374	828.557	-1,63	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 Rh1h2 Nd3e5 Qd2b2 a7a6 Rh2c2 Kb8a7 d5d6 Bc5xd6 Rc2c3 Bd6a3 Qb2d2 Re3xc3 Qd2xc3 Ne5c6 Qc3d2 Qb6c5 Qd2e1 Qc5f8 Qe1e4 Qf8g7 Qe4e3+ Ka7a8 Qe3e8+ Nc6b8 Kb1c2 Qg7b2+ Kc2d3 f7f5 Qe8e2 Qb2f6 Kd3c2 f5xg4 f3xg4 Qf6f4 Kc2b1 Nb8c6 Rd1f1 Qf4g5 Rf1d1 h7h6 Qe2e8+ Ka8a7 Qe8e4
 46/71+	07:55	 394.267.715	829.099	-1,54	Qe2f2
 46/82	08:25	 419.458.810	829.896	-1,57	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 Rh1h2 Nd3e5 Qd2b2 a7a6 Rh2c2 Kb8a7 d5d6 Bc5xd6 Rc2c3 Bd6a3 Qb2d2 Re3xc3 Qd2xc3 Ne5c6 Qc3e1 Ba3b4 Qe1f1 Bb4e7 Qf1d3 Be7f6 Qd3d6 Bf6e5 Qd6d2 Be5d4 Qd2d3 h7h6 f3f4 Bd4g7 Qd3h7 Bg7f6 g4g5 h6xg5 f4xg5 Bf6xg5 Qh7xf7 Qb6e3 Qf7f5 Qe3e2 Qf5c5+ Ka7b8 Qc5f8+ Kb8c7 Qf8f7+ Kc7b6 Qf7f1 Qe2xh5 Qf1f2+ Kb6c7 Rd1f1 Bg5e7 Qf2f5 Qh5h8 Qf5f4+ Kc7b6
 47/67-	08:52	 440.300.714	827.356	-1,65	Qe2f2 Re8e3
 47/72+	09:01	 447.652.160	827.439	-1,57	Qe2f2
 47/78	09:47	 485.682.326	826.521	-1,67	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 Rh1h2 Nd3e5 Qd2b2 a7a6 Rh2c2 Kb8a7 d5d6 Bc5xd6 Rc2c3 Bd6a3 Qb2d2 Re3xc3 Qd2xc3 Ne5c6 Qc3e1 Ba3b4 Qe1e2 Bb4c5 Qe2b2 Bc5d4 Qb2c2 Bd4f6 Rd1c1 Bf6g5 Rc1d1 h7h6 Qc2c3 a6a5 Qc3c4 Bg5f6 Rd1c1 Qb6d8 Qc4e4 Qd8d6 Qe4e3+ Ka7a8 Rc1c4 Qd6d1+ Rc4c1 Qd1d8 Qe3e4 Qd8d2 Rc1c2 Qd2d6 Rc2c4 Nc6b4
 48/81	11:12	 551.786.652	820.498	-1,67	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 d5d6 Bc5xd6 Qd2c3 Bd6e5 Qc3c4 Qb6c7 f3f4 Nd3xf4 Rh1e1 Re3xe1 Qc4xc7+ Kb8xc7 Rd1xe1 Kc7d6 a2a4 Nf4d5 Kb1c2 Kd6e6 Kc2d3 Nd5f6 Re1g1 Nf6d7 Rg1e1 Ke6d5 Kd3e3 a7a5 Re1d1+ Kd5e6 Ke3f3 h7h6
 49/81	11:29	 564.260.055	817.962	-1,67	Qe2f2 Re8e3 Nd7c5 Bg7d4 Qf2d2 Bd4xc5 Nh4xf5 Rd8e8 d5d6 Re8e5 Nf5e7+ Kc8b8 d6d7 Qa5d8 Ne7d5 Re5xd5 c4xd5 Qd8xd7 g2g4 Qd7d6 h2h4 Qd6g6+ Bf1d3 Nb4xd3 h4h5 Qg6b6 d5d6 Bc5xd6 Qd2c3 Bd6e5 Qc3c4 Qb6c7 f3f4 Nd3xf4 Rh1e1 Re3xe1 Qc4xc7+ Kb8xc7 Rd1xe1 Kc7d6 a2a4 Nf4d5 Kb1c2 Kd6e6 Kc2d3 Nd5f6 Re1g1 Nf6d7 Rg1e1 Ke6d5 Kd3e3 a7a5 Re1d1+ Kd5e6 Ke3f3 h7h6

Regards from Spain.

Ajedrecista.

[rj329]

Stockfish's latest version identifies white as losing on the first position you posted.

Code: Select all

FEN: 2kr3r/pp1b1pbp/5N2/q2P1p2/1nP4N/1P3P2/P3Q1PP/1K1R1B1R w - - 0 1

Stockfish_23072822_x64_avx2:
NNUE evaluation using nn-c38c3d8d3920.nnue
 1/1	00:00	 533	267k	-1.13	Nf6xd7
 2/2	00:00	 876	438k	-1.13	Nf6xd7
 3/2	00:00	 1k	673k	-0.82	Nf6xd7
 4/3	00:00	 2k	943k	-0.19	Nf6xd7 Rd8xd7 Nh4xf5
 5/4	00:00	 3k	1,481k	+0.15	Nf6xd7 Rd8xd7 Nh4xf5
 6/4	00:00	 4k	2,002k	+0.28	Nf6xd7 Rd8xd7 Nh4xf5
 7/5	00:00	 7k	2,244k	+1.14	Nf6xd7 Rd8xd7 Nh4xf5
 8/7	00:00	 12k	4,016k	+1.49	Nf6xd7 Rh8-e8 Qe2-d2 Kc8xd7 Nh4xf5
 9/8	00:00	 18k	4,499k	+1.66	Nf6xd7 Rh8-e8 Qe2-d2 Rd8xd7 Nh4xf5
 10/11	00:00	 41k	5,119k	+2.05	Nf6xd7 Bg7-c3 Nh4xf5 Rh8-e8 Qe2-f2 Rd8xd7 Bf1-d3
 11/11	00:00	 70k	5,800k	+1.88	Nf6xd7 Rd8xd7 Nh4xf5 Bg7-f6 Qe2-d2 Kc8-b8 Bf1-d3 Rd7-c7
 12/16	00:00	 118k	5,386k	+1.45	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-e1 Qf2-b2 Be1xh4 Nc5-a4 f5-f4 a2-a3
 13/21	00:00	 199k	5,234k	+1.38	Nf6xd7 Rh8-e8 Qe2-f2 Re8-e3 Bf1-d3 Rd8xd7 Nh4xf5 Re3xd3 Nf5xg7 Rd3-c3 Rh1-e1 Rc3-c2 Re1-e8+ Rd7-d8 Re8xd8+ Kc8xd8 Qf2-h4+ Kd8-c8 a2-a4 Rc2-c3
 14/25	00:00	 266k	5,213k	+1.24	Nf6xd7 Rh8-e8 Qe2-f2 Re8-e3 Bf1-d3 Rd8xd7 Nh4xf5 Re3xd3 Nf5xg7 Rd3-c3 Rh1-e1 Rc3-c2 Re1-e8+ Rd7-d8 Re8xd8+ Kc8xd8 Qf2-h4+ Kd8-c8 a2-a4 Rc2-c3 Qh4-g4+ Kc8-b8 Qg4-f4+ Kb8-a8
 15/24	00:00	 435k	5,874k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-e1 Qf2-b2 Be1-c3
 16/13	00:00	 466k	5,970k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-e1 Qf2-b2 Be1-c3
 17/12	00:00	 520k	6,117k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-e1 Qf2-b2 Be1-c3
 18/11	00:00	 543k	6,168k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 19/14	00:00	 586k	6,298k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-e1 Qf2-b2 Be1-c3 Qb2-f2
 20/11	00:00	 607k	6,322k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-d4
 21/11	00:00	 630k	6,297k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-d4
 22/11	00:00	 657k	6,195k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-d4
 23/12	00:00	 801k	6,072k	 0.00	Nf6xd7 Rh8-e8 Qe2-f2 Bg7-d4 Qf2-d2 Re8-e3 Nd7-c5 Bd4-c3 Qd2-f2 Bc3-d4 Qf2-d2
 24/19	00:00	 951k	6,022k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 25/11	00:00	 1,027k	5,971k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 26/11	00:00	 1,062k	6,001k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 27/12	00:00	 1,319k	5,996k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 28/10	00:00	 1,635k	6,011k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 29/11	00:00	 1,865k	6,054k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 30/11	00:00	 1,944k	6,075k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 31/11	00:00	 2,237k	6,046k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 32/10	00:00	 2,418k	6,107k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 33/10	00:00	 2,632k	6,135k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 34/10	00:00	 2,850k	6,051k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 35/11	00:00	 3,302k	6,036k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 36/11	00:00	 4,790k	5,709k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 37/10	00:01	 6,400k	5,585k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 38/11	00:01	 6,957k	5,448k	 0.00	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 39/11	00:01	 8,483k	5,299k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4-c3
 40/10	00:02	 10,399k	5,107k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 41/10	00:02	 13,538k	5,078k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 42/10	00:04	 20,186k	4,710k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 43/10	00:05	 24,856k	4,567k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 44/10	00:07	 31,856k	4,034k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 45/10	00:08	 33,218k	3,960k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 46/43	00:17	 59,858k	3,440k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4xc5 Nh4xf5 Rh8-e8 d5-d6 Re8-e5 Nf5-e7+ Kc8-d8 Ne7-d5 Re5xd5 c4xd5 Bc5-d4 Bf1-c4 b7-b5 a2-a4 b5xc4 Qd2xd4 Re3xb3+ Kb1-c1 Qa5xa4 Qd4-h4+ f7-f6 Qh4xf6+ Kd8-c8 d6-d7+ Kc8xd7 Qf6-f7+ Kd7-d8 Qf7-f8+ Kd8-c7 Qf8-e7+ Kc7-c8 Qe7-f8+ Kc8-c7
 47/40	00:20	 69,643k	3,441k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 48/42	00:22	 78,387k	3,468k	 0.00	Nf6xd7 Rd8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 49/86-	00:37	 132,785k	3,565k	-0.03	Nf6xd7 Rd8-e8
 49/86-	00:38	 138,591k	3,582k	-0.06	Nf6xd7 Rd8-e8
 49/86-	01:15	 281,188k	3,731k	-1.04	Nf6xd7 Rd8-e8
 49/86-	02:29	 554,800k	3,722k	-1.40	Nf6xd7 Rh8-e8
 49/89	03:08	 700,662k	3,709k	-1.48	Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2 Bd4xc5 Nh4xf5 Rd8-e8 d5-d6 Re8-e5 Nf5-e7+ Kc8-b8 d6-d7 Qa5-d8 Ne7-d5 Re5xd5 c4xd5 Qd8xd7 g2-g4 Qd7-d6 h2-h4 Qd6-g6+ Bf1-d3 Nb4xd3 h4-h5 Qg6-b6 Rh1-h2 Nd3-e5 Qd2-b2 a7-a5 d5-d6 Bc5xd6 Rh2-e2 Bd6-a3 Qb2-d2 Re3-d3 Qd2-c2 Rd3xd1+ Qc2xd1 Ne5-c6 Re2-d2 Kb8-a7 Rd2-d3 a5-a4 Qd1-e2 Ba3-c5 Qe2-e4 Bc5-d4 Qe4-f4 a4-a3 Rd3-d1 Bd4-c3 Rd1-d3 Bc3-b4 Qf4-e3 Bb4-c5 Qe3-c1 f7-f6 Qc1-f4 Nc6-b4 Rd3-c3 Nb4-a6 Rc3-d3 Qb6-e6 Qf4-e4

[rj329]

Does take a while to find the non-losing move 19.Nf2 though.

Code: Select all

FEN: 2kr1b1r/pp1b1p1p/8/q2P1p2/1nP1N2N/1P3P2/P3Q1PP/1K1R1B1R w - - 0 19

Stockfish_23072822_x64_avx2:
NNUE evaluation using nn-c38c3d8d3920.nnue
[...]
 57/12	04:41	 959,555k	3,411k	 0.00	Ne4-f6 Bf8-g7 Nf6xd7 Rh8-e8 Qe2-d2 Re8-e3 Nd7-c5 Bg7-c3 Qd2-f2 Bc3-d4 Qf2-d2
 58/35-	04:53	 1,001,410k	3,417k	-0.03	Ne4-f6 Bf8-g7
 58/35-	05:03	 1,039,561k	3,420k	-0.06	Ne4-f6 Bf8-g7
 58/52-	05:15	 1,080,995k	3,424k	-0.10	Ne4-f6 Bf8-g7
 58/70+	07:19	 1,485,527k	3,383k	-0.06	Ne4-f2
 58/73-	11:12	 2,220,014k	3,300k	-0.15	Ne4-f2 Bf8-g7
 58/78-	12:46	 2,472,448k	3,228k	-0.24	Ne4-f2 Bf8-g7
 58/78+	13:56	 2,671,663k	3,196k	-0.15	Ne4-f2
 58/87	15:19	 2,879,721k	3,131k	-0.08	Ne4-f2 Bf8-g7 Nf2-d3 Qa5-b6 Nd3xb4 Qb6-f6 Qe2-d2 a7-a5 Qd2-d4 Qf6xd4 Rd1xd4 Bg7xd4 Nb4-d3 b7-b5 c4-c5 f5-f4 c5-c6 Bd7-e8 Nh4-f5 Bd4-f6 Nd3xf4 Bf6-g5 g2-g3 Kc8-c7 Nf5-e3 Bg5xf4 g3xf4 Be8xc6 d5xc6 Rh8-e8 Ne3-c2 Rd8-d1+ Kb1-b2 Re8-e6 Rh1-g1 Re6xc6 Nc2-e3 Rd1-d2+ Kb2-b1 Rc6-c3 Rg1-g2 Rd2xg2 Ne3xg2 Rc3xf3 Bf1xb5 Rf3-h3 Kb1-c2 h7-h5 Ng2-e1 Rh3xh2+ Kc2-d3 Rh2xa2 Ne1-f3 Kc7-d6 Bb5-c4 Kd6-e7 Kd3-e4 Ke7-f6 Ke4-e3 Ra2-c2 Nf3-g5 h5-h4 Bc4xf7 h4-h3 Ng5xh3 Rc2-c3+ Ke3-d4 Rc3xh3 Bf7-c4 Kf6-f5 Kd4-c5 Rh3xb3 Bc4xb3 Kf5xf4 Kc5-b5 a5-a4 Kb5xa4 Kf4-f3 Ka4-a5 Kf3-f2 Ka5-a6 Kf2-e3 Ka6-a5 Ke3-d4 Ka5-a6 Kd4-c5 Ka6-a5 Kc5-c6