Another position Stockfish misevaluates (from my games).

[pepechuy]

Hi.

I am aware that there are hundreds of positions known to be misevaluated by some engine (or engines).
I am posting this because it appeared in a game played yesterday over-the-board; by me, against another human player.

[pgn]
[Event "Campeonato club Aleph 2022"]
[Site "Tijuana, B. C."]
[Date "2022.11.05."]
[Round "7"]
[White "Garcia Ruvalcaba, Jose de Jesus"]
[Black "Peinado Enciso, Nestor"]
[Result "1/2-1/2"]
[ECO "B73/02"]
[Opening "Sicilian: dragon, classical (8.O-O O-O 9.f4)"]

1. e4 c5 2. Nf3 g6 3. d4 cxd4 4. Nxd4 Nc6 5. Be3 Nf6 6. Nc3 Bg7 7. f4 d6 8. Be2
O-O 9. O-O Bd7 10. g4 Nxd4 11. Bxd4 Bc6 12. Bf3 Qa5 13. g5 Nd7 14. Bxg7 Kxg7 15.
Qd4+ Kg8 16. Nd5 Bxd5 17. exd5 Qb6 18. Qxb6 Nxb6 19. Rfe1 Rfe8 20. b3 Rac8 21.
c4 Kf8 22. Bg4 Rc7 23. Kf2 a5 24. Ke3 Nd7 25. Bxd7 Rxd7 26. Kd4 Rc7 27. Re3 Rec8
28. Rae1 b6 29. a4 Rd7 30. f5 gxf5 31. Rf1 Kg7 32. Rxf5 Kg6 33. Ke4 Re8 34. Kf4
Rf8 35. Kg4 Rb7 36. Ref3 Rbb8 37. h4 Rbc8 38. h5+ Kg7 39. Re3 Rc7 40. Rf4 Rb7
41. Rfe4 Re8 42. Kf5 Rc7 43. b4 axb4 44. h6+ Kf8 45. Rb3 Ra8 46. Rxb4 Ra6 47.
Re3 Rc8 48. Reb3 Re8 49. Rxb6 Rxa4 50. Rc6 Ra1 51. Rf3 Re1 52. Rc7 Re5+ 53. Kg4
Re4+ 54. Rf4 Rxf4+ 55. Kxf4 Kg8 56. Kf5 Kf8 57. Ke4 Rb8 58. Kd4 Rd8 59. Rb7 Rc8
60. Kc3 Ke8 61. Kb4 Kd8 62. Kb5 Ke8 63. Kb4 Kd8 64. Kb5 Rc5+ 65. Kb4 Rc8 1/2-1/2
[/pgn]

I am referring in particular to the position after 42... Rc7
The game can be found, analyzed by Stockfish, here:

https://lichess.org/CPvqj8nE/white#84

Stockfish marks my move 43. b4 as a blunder. According to it, the evaluation drops from 2.5 to 0.1
It suggests 43. h6 as the best move.

However, if you turn the analysis on, make 43. h6, and follow the suggested lines, you will see that White makes absolutely no progress at all.
Basically, the position is even, but Stockfish evaluates it as a big advantage for White.
That is because I had a lot more space. But there is no way to transform that advantage.

Greetings.

[Jouni]

Latest SF is quite good:

Analysis by Stockfish 051122:
...
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Rb7 48.Kc3 Rc7 49.Rf5 Rb7 50.Re3 Rc7 51.Kd2 Rb7 52.Re4 Re8 53.Kd3 Rf8 54.Ke2 Re8 55.Kf3 Rc8 56.Kg4 Rcb8 57.Ref4 Rf8 58.Kf3 Rc7 59.Ke4 Rb7 60.Kd4 Ra7 61.Rf1 Rb7
+/- (1.52) Depth: 41/52 00:00:05 33818kN, tb=2748
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Rb7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Rc7 51.Kb2 Rb7 52.Re4 Rc7 53.Rff4 Rfc8 54.Rf1 Rb7 55.Ref4 Rf8 56.R4f3 Rc7 57.Re3 Rb7 58.Rf4 Rc7 59.Rff3 Re8 60.Rf1 Rb7 61.Rfe1 Ra7 62.Rf3 Rc7 63.Rf4 Rec8 64.Ref1 Rf8 65.R4f3
+/- (1.52) Depth: 42/47 00:00:05 36606kN, tb=3043
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Rb7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Rc7 51.Kb2 Rb7 52.Re4 Rc7 53.Rff4 Rfc8 54.Rf1 Rb7 55.Ref4 Rf8 56.Kc2 Rc7 57.Re4 Rb7 58.Rf5 Re8 59.Rf3 Rc7 60.Kd3 Rf8 61.Kd2 Rfc8 62.Rf5 Rf8 63.Rff4 Rb7 64.Rf3 Re8 65.Rf1
+/- (1.52) Depth: 43/45 00:00:06 37908kN, tb=3166
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Kc3 Rbc8 56.Re1 Kf8 57.Kb3 Re8 58.Re3 Kg8 59.b5 Rec8 60.Ref3 Rf8 61.Rf1 Ra7 62.Re4 Rc8 63.Rfe1 Kf8 64.Kc3 Re8 65.Rf1 Rc7 66.Ref4 e6
+/- (1.52) Depth: 44/50 00:00:07 43385kN, tb=4469
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.R1f3 Ra7 58.Re3 Rc8 59.Rfe4 Kf8 60.Rg3 Re8 61.Rf3 Rc7 62.Rf1 Kg8 63.Kc3 Rec8 64.b5 Re8 65.Rfe1 Rec8 66.Kd3 Re8
+/- (1.52) Depth: 45/49 00:00:07 46547kN, tb=5632
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.R1f3 Ra7 58.Re3 Rc8 59.Rfe4 Kf8 60.Rg3 Re8 61.Rf3 Rc7 62.Rf1 Kg8 63.Kc3 Rec8 64.b5 Re8 65.Rfe1 Rec8 66.Kd3 Re8 67.Rf4
+/- (1.52) Depth: 46/49 00:00:08 52452kN, tb=6853
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.R1f3 Ra7 58.Re3 Rc8 59.Rfe4 Kf8 60.Rg3 Re8 61.Rf3 Rc7 62.Rf1 Kg8 63.Kc3 Rec8 64.b5 Re8 65.Rfe1 Rec8 66.R1e3 Re8 67.Kd3
+/- (1.52) Depth: 47/49 00:00:09 57746kN, tb=7574
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.R1f3 Ra7 58.Re3 Rc8 59.Rfe4 Kf8 60.Rg3 Re8 61.Rf3 Rc7 62.Rf1 Kg8 63.Kc3 Rec8 64.b5 Rf8 65.Kd2 Rfc8 66.Kd3 Re8 67.Rf3 Rf8 68.Rfe3
+/- (1.52) Depth: 48/53 00:00:10 68405kN, tb=8866
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.R1f3 Ra7 58.b5 Rb7 59.Kb2 Rc7 60.Rf1 Rc5 61.Re4 Rc7 62.Kc3 Rfc8 63.Rf3 Rf8 64.Kd3 Re8 65.Ref4 Rf8 66.Ke2 Rcc8 67.Re4 Rfe8
+/- (1.52) Depth: 49/53 00:00:11 72540kN, tb=9694
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.R1f3 Ra7 58.Re4 Rc8 59.b5 Re8 60.Rff4 Rc7 61.Kc3 Rf8 62.Rf5 Re8 63.Kd3 Rf8 64.Rf2 Re8 65.Ref4 Rf8 66.R2f3 Rcc8 67.Re4 Rfe8 68.Rfe3 Rc7 69.Kd2
+/- (1.52) Depth: 50/59 00:00:12 80601kN, tb=10788
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.b4 Rc7 53.Kb3 Rfc8 54.Rff4 Rb8 55.Re1 Ra8 56.Ref1 Rf8 57.Re4 Rfc8 58.Rfe1 Kf8 59.Rf4 Kg8 60.Re3 Ra7 61.Ref3 Rf8 62.Kc3 Rc7 63.Kd3 Ra7 64.b5 Rc7 65.Re3 Re8 66.Rfe4 Kf8 67.Rf3 Kg8 68.Rf5 Rf8 69.Ke3 Rfc8 70.Rff4 Kf8
+/- (1.52) Depth: 51/58 00:00:16 102mN, tb=16057
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rff4 Rd7 53.Rf1 Rc7 54.Rfe1 Re8 55.Kb2 Kf8 56.Rf1 Kg8 57.Rf5 Rec8 58.Ref4 Rf8 59.Rf1 Rcc8 60.Re1 Rc7 61.Rf4 Rfc8 62.Re3 Rb7 63.Rfe4 Re8 64.Kc3 Kf8 65.Rf3 Rc7 66.Kd3 Kg8 67.Ref4 Rf8 68.Kc3 Ra7 69.Re3 Rc7 70.Rfe4 Re8 71.b4 Rec8
+/- (1.52) Depth: 52/57 00:00:18 114mN, tb=19043
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rf1 Rc7 53.Kb2 Rfc8 54.Ka2 Re8 55.Rfe1 Kf8 56.Kb2 Kg8 57.R1e3 Kf8 58.Rf4 Kg8 59.Rf5 Rec8 60.Ref3 Rf8 61.R3f4 Rb7 62.Rf1 Ra7 63.R5f3 Rb7 64.Re3 Re8 65.Kc3 Rf8 66.b4 Rc7 67.Ref3 Ra7 68.Re1 Rc7 69.Re4 Re8 70.Rfe3 Rec8
+/- (1.52) Depth: 53/56 00:00:19 120mN, tb=20796
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rf1 Rc7 53.Kb2 Re8 54.Ka2 Kf8 55.Ree1 Kg8 56.Re3 Rf8 57.Rf5 Re8 58.Rf4 Kf8 59.Kb2 Kg8 60.Rfe4 Kf8 61.Kc3 Kg8 62.Re1 Kf8 63.Rf4 Kg8 64.Ref1 Rf8 65.Rf5 Rcc8 66.Re1 Rfe8 67.Kd4 Rc7 68.Kd3 Rb7 69.Ref1 Rf8
+/- (1.52) Depth: 54/55 00:00:20 129mN, tb=27725
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rf1 Rc7 53.Kb2 Re8 54.Ka2 Kf8 55.Ree1 Kg8 56.Re3 Rf8 57.Rf5 Re8 58.Rf4 Kf8 59.Kb2 Kg8 60.Kc3 Rec8 61.Kd2 Re8 62.Rf5 Rf8 63.Rf1 Re8 64.Rf4 Rf8 65.Rfe4 Re8 66.Kc3 Kf8 67.Rf3 Kg8 68.b4 Rec8 69.Rff4 Rf8 70.Rf5 Re8 71.bxa5 bxa5
+/- (1.52) Depth: 55/58 00:00:22 142mN, tb=31596
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rf1 Rc7 53.Kb2 Re8 54.Ka2 Kf8 55.Ree1 Kg8 56.Re3 Rf8 57.Rf5 Re8 58.Rf4 Kf8 59.Kb2 Kg8 60.Kc3 Rb7 61.Rf1 Rc7 62.Kd2 Rf8 63.Rfe1 Re8 64.Re4 Kf8 65.Kc3 Rec8 66.Rf4 Kg8 67.Re3 Re8 68.Rfe4 Kf8 69.Rf3 Kg8 70.b4 Rec8 71.Kb3 Re8 72.Rfe3
+/- (1.52) Depth: 56/61 00:00:24 156mN, tb=38516
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rf1 Rc7 53.Kb2 Re8 54.Ka2 Kf8 55.Ree1 Kg8 56.Re3 Rf8 57.Rf5 Re8 58.Rf4 Kf8 59.Kb2 Kg8 60.Kc3 Rb7 61.Rf1 Rc7 62.Kd2 Rf8 63.Rfe1 Re8 64.Kd3 Kf8 65.Rf3 Kg8 66.Ref1 Rf8 67.Kc3 Rb7 68.Rf4 Rc7 69.Rf5 Rcc8 70.R5f3 Rc7 71.b4 Ra7 72.Rf4 Rc7 73.Kd3 Rb7
+/- (1.52) Depth: 57/62 00:00:27 169mN, tb=45606
43.h6+ Kf8 44.Rf4 Rec8 45.Ke4 Kg8 46.Kd3 Rf8 47.Ref3 Ra7 48.Kc3 Rc7 49.Rf5 Rb7 50.R3f4 Ra7 51.Re4 Rb7 52.Rf1 Rc7 53.Kb2 Re8 54.Ka2 Kf8 55.Ree1 Kg8 56.Re3 Rf8 57.Rf5 Re8 58.Rf4 Kf8 59.Kb2 Kg8 60.Kc3 Rb7 61.Rf1 Rc7 62.Kd2 Rf8 63.Rfe1 Re8 64.Kd3 Kf8 65.Rf1 Kg8 66.Re4 Rf8 67.Ref4 Rcc8 68.Re1 Rfe8 69.Kc3 Rc7 70.Ref1 Rf8 71.Rf5 Rb7 72.b4 Rc7 73.bxa5 bxa5 74.Kd3 Rb7
+/- (1.52) Depth: 58/64 00:00:31 194mN, tb=61764

No progress = draw.

[Kooper]

The position is uneven and there is a way to transform that advantage.

Dark Sister 2.0 managed to progress it against the latest Stockfish.
[pgn][White "Dark Sister 2.0"]
[Black "Stockfish dev-20221107-nogit"]
[Result "1-0"]
[SetUp "1"]
[FEN "4r3/2r1ppkp/1p1p4/p2P1KPP/P1P1R3/1P2R3/8/8 w - -"]

1. h6+ Kg8 2. Kg4 Rd7 3. Kf3 Rb7 4. Ke2 {+2.75/31 19s} Rd7
{+1.44/29 20s} 5. Kd3 {+2.70/28 7s} Rc7 {+1.43/29 20s}
6. Kc3 {+2.69/29 11s} Ra7 {+1.43/38 9s} 7. Re2 {+2.94/28
11s} Rc7 {+1.43/38 8s} 8. Rf2 {+3.00/28 10s} Rf8 {+1.43/39
9s} 9. Ref4 {+3.04/26 8s} Rd7 {+1.43/42 9s} 10. b4
{+3.36/24 8s} Ra7 {+1.38/33 8s} 11. bxa5 {+3.44/27 25s}
bxa5 {+1.41/26 12s} 12. Rb2 {+3.54/24 7s} Rc8 {+2.35/30
1:37m} 13. Rb5 {+3.71/21 8s} Kf8 {+2.46/25 32s} 14. Kd3
{+3.85/22 10s} Kg8 {+2.63/27 58s} 15. Rf2 {+4.44/22 9s} e6
{+2.75/21 9s} 16. Rf4 {+4.93/22 14s} Rac7 {+3.21/25 32s}
17. Rxa5 {+5.21/21 9s} Rb7 {+3.38/21 11s} 18. Rb5 {+5.34/23
8s} Ra7 {+3.40/19 1s} 19. dxe6 {+5.65/24 23s} fxe6
{+3.27/17 1s} 20. a5 {+5.89/22 13s} Rca8 {+2.88/17 2s}
21. Rd4 {+5.87/20 8s} d5 {+3.52/21 11s} 22. cxd5 {+5.97/20
11s} exd5 {+3.40/24 4s} 23. Rdxd5 {+6.46/22 9s} Kf7
{+3.98/21 12s} 24. Kc4 {+7.11/22 22s} Kg6 {+4.00/16 1s}
25. Rb6+ {+7.21/17 5s} Kh5 {+3.83/18 6s} 26. Kb4 {+7.36/19
12s} Rf8 {+4.18/20 10s} 27. g6+ {+8.18/19 9s} Kxh6
{+4.73/18 5s} 28. gxh7+ {+8.63/20 11s} Kg7 {+4.54/19 3s}
29. a6 {+9.70/20 10s} Kh8 {+5.39/20 8s} 30. Rdb5 {+9.49/35
37s} Raa8 {+5.35/22 5s} 31. Ka5 {+9.54/29 7s} Kxh7
{+5.26/20 1s} 32. Rb7+ {+13.00/28 1:01m} Kg6 {+5.22/23 3s}
33. a7 {+14.68/18 2s} Rf3 {+5.20/25 2s} 34. Ka6 {+14.68/19
2s} Ra3+ {+5.12/30 4s} 35. Ra5 {+14.78/17 2s} Rxa5+
{+5.20/32 3s} 36. Kxa5 {+15.27/17 4s} Kf5 {+5.19/29 4s}
37. Ka6 {+19.60/18 4s} Kf4 {+8.21/29 20s} 38. Rb8 {+M25/24
3s} Rxa7+ {+M32/27 8s} 39. Kxa7 {+M21/29 4s} Ke4 {+M22/28
3s} 40. Kb6 {+M20/29 10s} Kd5 {+M22/25 1s} 41. Ra8 {+M18/30
13s} Kd4 {+M19/30 4s} 42. Kc6 {+M17/30 9s} Ke4 {+M18/29 2s}
43. Kc5 {+M16/28 2s} Kf4 {+M15/31 4s} 44. Kd4 {+M14/28 12s}
Kf5 {+M14/31 2s} 45. Ra6 {+M13/28 2s} Kf4 {+M13/31 3s}
46. Rf6+ {+M12/28 2s} Kg5 {+M11/32 7s} 47. Ke5 {+M11/28 2s}
Kg4 {+M9/32 4s} 48. Rf8 {+M9/28 4s} Kg3 {+M8/33 5s} 49. Ke4
{+M8/28 4s} Kg2 {+M7/34 4s} 50. Kf4 {+M7/30 3s} Kf2 {+M6/38
3s} 51. Re8 {+M6/36 4s} Kg2 {+M5/72 3s} 52. Re2+ {+M5/144
4s} Kf1 {+M4/245 1s} 53. Kf3 {+M4/245 1s} Kg1 {+M3/245 0s}
54. Re1+ {+M3/245 0s} Kh2 {+M2/245 0s} 55. Rc1 {+M2/245 0s}
Kh3 {+M1/245 0s} 56. Rh1# {+M1/245 0s} 1-0[/pgn]

[pepechuy]

The position is uneven and there is a way to transform that advantage.

Dark Sister 2.0 managed to progress it against the latest Stockfish.
[pgn][White "Dark Sister 2.0"]
[Black "Stockfish dev-20221107-nogit"]
[Result "1-0"]
[SetUp "1"]
[FEN "4r3/2r1ppkp/1p1p4/p2P1KPP/P1P1R3/1P2R3/8/8 w - -"]

1. h6+ Kg8 2. Kg4 Rd7 3. Kf3 Rb7 4. Ke2 {+2.75/31 19s} Rd7
{+1.44/29 20s} 5. Kd3 {+2.70/28 7s} Rc7 {+1.43/29 20s}
6. Kc3 {+2.69/29 11s} Ra7 {+1.43/38 9s} 7. Re2 {+2.94/28
11s} Rc7 {+1.43/38 8s} 8. Rf2 {+3.00/28 10s} Rf8 {+1.43/39
9s} 9. Ref4 {+3.04/26 8s} Rd7 {+1.43/42 9s} 10. b4
{+3.36/24 8s} Ra7 {+1.38/33 8s} 11. bxa5 {+3.44/27 25s}
bxa5 {+1.41/26 12s} 12. Rb2 {+3.54/24 7s} Rc8 {+2.35/30
1:37m} 13. Rb5 {+3.71/21 8s} Kf8 {+2.46/25 32s} 14. Kd3
{+3.85/22 10s} Kg8 {+2.63/27 58s} 15. Rf2 {+4.44/22 9s} e6
{+2.75/21 9s} 16. Rf4 {+4.93/22 14s} Rac7 {+3.21/25 32s}
17. Rxa5 {+5.21/21 9s} Rb7 {+3.38/21 11s} 18. Rb5 {+5.34/23
8s} Ra7 {+3.40/19 1s} 19. dxe6 {+5.65/24 23s} fxe6
{+3.27/17 1s} 20. a5 {+5.89/22 13s} Rca8 {+2.88/17 2s}
21. Rd4 {+5.87/20 8s} d5 {+3.52/21 11s} 22. cxd5 {+5.97/20
11s} exd5 {+3.40/24 4s} 23. Rdxd5 {+6.46/22 9s} Kf7
{+3.98/21 12s} 24. Kc4 {+7.11/22 22s} Kg6 {+4.00/16 1s}
25. Rb6+ {+7.21/17 5s} Kh5 {+3.83/18 6s} 26. Kb4 {+7.36/19
12s} Rf8 {+4.18/20 10s} 27. g6+ {+8.18/19 9s} Kxh6
{+4.73/18 5s} 28. gxh7+ {+8.63/20 11s} Kg7 {+4.54/19 3s}
29. a6 {+9.70/20 10s} Kh8 {+5.39/20 8s} 30. Rdb5 {+9.49/35
37s} Raa8 {+5.35/22 5s} 31. Ka5 {+9.54/29 7s} Kxh7
{+5.26/20 1s} 32. Rb7+ {+13.00/28 1:01m} Kg6 {+5.22/23 3s}
33. a7 {+14.68/18 2s} Rf3 {+5.20/25 2s} 34. Ka6 {+14.68/19
2s} Ra3+ {+5.12/30 4s} 35. Ra5 {+14.78/17 2s} Rxa5+
{+5.20/32 3s} 36. Kxa5 {+15.27/17 4s} Kf5 {+5.19/29 4s}
37. Ka6 {+19.60/18 4s} Kf4 {+8.21/29 20s} 38. Rb8 {+M25/24
3s} Rxa7+ {+M32/27 8s} 39. Kxa7 {+M21/29 4s} Ke4 {+M22/28
3s} 40. Kb6 {+M20/29 10s} Kd5 {+M22/25 1s} 41. Ra8 {+M18/30
13s} Kd4 {+M19/30 4s} 42. Kc6 {+M17/30 9s} Ke4 {+M18/29 2s}
43. Kc5 {+M16/28 2s} Kf4 {+M15/31 4s} 44. Kd4 {+M14/28 12s}
Kf5 {+M14/31 2s} 45. Ra6 {+M13/28 2s} Kf4 {+M13/31 3s}
46. Rf6+ {+M12/28 2s} Kg5 {+M11/32 7s} 47. Ke5 {+M11/28 2s}
Kg4 {+M9/32 4s} 48. Rf8 {+M9/28 4s} Kg3 {+M8/33 5s} 49. Ke4
{+M8/28 4s} Kg2 {+M7/34 4s} 50. Kf4 {+M7/30 3s} Kf2 {+M6/38
3s} 51. Re8 {+M6/36 4s} Kg2 {+M5/72 3s} 52. Re2+ {+M5/144
4s} Kf1 {+M4/245 1s} 53. Kf3 {+M4/245 1s} Kg1 {+M3/245 0s}
54. Re1+ {+M3/245 0s} Kh2 {+M2/245 0s} 55. Rc1 {+M2/245 0s}
Kh3 {+M1/245 0s} 56. Rh1# {+M1/245 0s} 1-0[/pgn]

Hi.

¡Thank you!
I was wrongly assuming that there is no way to progress, simply because Stockfish did not find it.
I actually considered going with my king to the queenside; but several moves earlier, not at this point.

Now, I think this might be an actual example of a position that Stockfish misplays (with White), not just misevaluates.
Or perhaps at some point it tries the winning maneuver.

I am now interested in Dark Sister.

Greetings.

[gordonr]

The position is uneven and there is a way to transform that advantage.

Dark Sister 2.0 managed to progress it against the latest Stockfish.
[pgn][White "Dark Sister 2.0"]
[Black "Stockfish dev-20221107-nogit"]
[Result "1-0"]
[SetUp "1"]
[FEN "4r3/2r1ppkp/1p1p4/p2P1KPP/P1P1R3/1P2R3/8/8 w - -"]

1. h6+ Kg8 2. Kg4 Rd7 3. Kf3 Rb7 4. Ke2 {+2.75/31 19s} Rd7
{+1.44/29 20s} 5. Kd3 {+2.70/28 7s} Rc7 {+1.43/29 20s}
6. Kc3 {+2.69/29 11s} Ra7 {+1.43/38 9s} 7. Re2 {+2.94/28
11s} Rc7 {+1.43/38 8s} 8. Rf2 {+3.00/28 10s} Rf8 {+1.43/39
9s} 9. Ref4 {+3.04/26 8s} Rd7 {+1.43/42 9s} 10. b4
{+3.36/24 8s} Ra7 {+1.38/33 8s} 11. bxa5 {+3.44/27 25s}
bxa5 {+1.41/26 12s} 12. Rb2 {+3.54/24 7s} Rc8 {+2.35/30
1:37m} 13. Rb5 {+3.71/21 8s} Kf8 {+2.46/25 32s} 14. Kd3
{+3.85/22 10s} Kg8 {+2.63/27 58s} 15. Rf2 {+4.44/22 9s} e6
{+2.75/21 9s} 16. Rf4 {+4.93/22 14s} Rac7 {+3.21/25 32s}
17. Rxa5 {+5.21/21 9s} Rb7 {+3.38/21 11s} 18. Rb5 {+5.34/23
8s} Ra7 {+3.40/19 1s} 19. dxe6 {+5.65/24 23s} fxe6
{+3.27/17 1s} 20. a5 {+5.89/22 13s} Rca8 {+2.88/17 2s}
21. Rd4 {+5.87/20 8s} d5 {+3.52/21 11s} 22. cxd5 {+5.97/20
11s} exd5 {+3.40/24 4s} 23. Rdxd5 {+6.46/22 9s} Kf7
{+3.98/21 12s} 24. Kc4 {+7.11/22 22s} Kg6 {+4.00/16 1s}
25. Rb6+ {+7.21/17 5s} Kh5 {+3.83/18 6s} 26. Kb4 {+7.36/19
12s} Rf8 {+4.18/20 10s} 27. g6+ {+8.18/19 9s} Kxh6
{+4.73/18 5s} 28. gxh7+ {+8.63/20 11s} Kg7 {+4.54/19 3s}
29. a6 {+9.70/20 10s} Kh8 {+5.39/20 8s} 30. Rdb5 {+9.49/35
37s} Raa8 {+5.35/22 5s} 31. Ka5 {+9.54/29 7s} Kxh7
{+5.26/20 1s} 32. Rb7+ {+13.00/28 1:01m} Kg6 {+5.22/23 3s}
33. a7 {+14.68/18 2s} Rf3 {+5.20/25 2s} 34. Ka6 {+14.68/19
2s} Ra3+ {+5.12/30 4s} 35. Ra5 {+14.78/17 2s} Rxa5+
{+5.20/32 3s} 36. Kxa5 {+15.27/17 4s} Kf5 {+5.19/29 4s}
37. Ka6 {+19.60/18 4s} Kf4 {+8.21/29 20s} 38. Rb8 {+M25/24
3s} Rxa7+ {+M32/27 8s} 39. Kxa7 {+M21/29 4s} Ke4 {+M22/28
3s} 40. Kb6 {+M20/29 10s} Kd5 {+M22/25 1s} 41. Ra8 {+M18/30
13s} Kd4 {+M19/30 4s} 42. Kc6 {+M17/30 9s} Ke4 {+M18/29 2s}
43. Kc5 {+M16/28 2s} Kf4 {+M15/31 4s} 44. Kd4 {+M14/28 12s}
Kf5 {+M14/31 2s} 45. Ra6 {+M13/28 2s} Kf4 {+M13/31 3s}
46. Rf6+ {+M12/28 2s} Kg5 {+M11/32 7s} 47. Ke5 {+M11/28 2s}
Kg4 {+M9/32 4s} 48. Rf8 {+M9/28 4s} Kg3 {+M8/33 5s} 49. Ke4
{+M8/28 4s} Kg2 {+M7/34 4s} 50. Kf4 {+M7/30 3s} Kf2 {+M6/38
3s} 51. Re8 {+M6/36 4s} Kg2 {+M5/72 3s} 52. Re2+ {+M5/144
4s} Kf1 {+M4/245 1s} 53. Kf3 {+M4/245 1s} Kg1 {+M3/245 0s}
54. Re1+ {+M3/245 0s} Kh2 {+M2/245 0s} 55. Rc1 {+M2/245 0s}
Kh3 {+M1/245 0s} 56. Rh1# {+M1/245 0s} 1-0[/pgn]

What if 10... axb4+ ? This was suggested by Stockfish 5th Nov 2022. It looks drawn.


[fen]5rk1/3rpp1p/1p1p3P/3P2P1/PpP2R2/2K5/5R2/8 w - - 0 11[/fen]

[Eelco de Groot]

The position is uneven and there is a way to transform that advantage.

Dark Sister 2.0 managed to progress it against the latest Stockfish.
[pgn][White "Dark Sister 2.0"]
[Black "Stockfish dev-20221107-nogit"]
[Result "1-0"]
[SetUp "1"]
[FEN "4r3/2r1ppkp/1p1p4/p2P1KPP/P1P1R3/1P2R3/8/8 w - -"]

1. h6+ Kg8 2. Kg4 Rd7 3. Kf3 Rb7 4. Ke2 {+2.75/31 19s} Rd7
{+1.44/29 20s} 5. Kd3 {+2.70/28 7s} Rc7 {+1.43/29 20s}
6. Kc3 {+2.69/29 11s} Ra7 {+1.43/38 9s} 7. Re2 {+2.94/28
11s} Rc7 {+1.43/38 8s} 8. Rf2 {+3.00/28 10s} Rf8 {+1.43/39
9s} 9. Ref4 {+3.04/26 8s} Rd7 {+1.43/42 9s} 10. b4
{+3.36/24 8s} Ra7 {+1.38/33 8s} 11. bxa5 {+3.44/27 25s}
bxa5 {+1.41/26 12s} 12. Rb2 {+3.54/24 7s} Rc8 {+2.35/30
1:37m} 13. Rb5 {+3.71/21 8s} Kf8 {+2.46/25 32s} 14. Kd3
{+3.85/22 10s} Kg8 {+2.63/27 58s} 15. Rf2 {+4.44/22 9s} e6
{+2.75/21 9s} 16. Rf4 {+4.93/22 14s} Rac7 {+3.21/25 32s}
17. Rxa5 {+5.21/21 9s} Rb7 {+3.38/21 11s} 18. Rb5 {+5.34/23
8s} Ra7 {+3.40/19 1s} 19. dxe6 {+5.65/24 23s} fxe6
{+3.27/17 1s} 20. a5 {+5.89/22 13s} Rca8 {+2.88/17 2s}
21. Rd4 {+5.87/20 8s} d5 {+3.52/21 11s} 22. cxd5 {+5.97/20
11s} exd5 {+3.40/24 4s} 23. Rdxd5 {+6.46/22 9s} Kf7
{+3.98/21 12s} 24. Kc4 {+7.11/22 22s} Kg6 {+4.00/16 1s}
25. Rb6+ {+7.21/17 5s} Kh5 {+3.83/18 6s} 26. Kb4 {+7.36/19
12s} Rf8 {+4.18/20 10s} 27. g6+ {+8.18/19 9s} Kxh6
{+4.73/18 5s} 28. gxh7+ {+8.63/20 11s} Kg7 {+4.54/19 3s}
29. a6 {+9.70/20 10s} Kh8 {+5.39/20 8s} 30. Rdb5 {+9.49/35
37s} Raa8 {+5.35/22 5s} 31. Ka5 {+9.54/29 7s} Kxh7
{+5.26/20 1s} 32. Rb7+ {+13.00/28 1:01m} Kg6 {+5.22/23 3s}
33. a7 {+14.68/18 2s} Rf3 {+5.20/25 2s} 34. Ka6 {+14.68/19
2s} Ra3+ {+5.12/30 4s} 35. Ra5 {+14.78/17 2s} Rxa5+
{+5.20/32 3s} 36. Kxa5 {+15.27/17 4s} Kf5 {+5.19/29 4s}
37. Ka6 {+19.60/18 4s} Kf4 {+8.21/29 20s} 38. Rb8 {+M25/24
3s} Rxa7+ {+M32/27 8s} 39. Kxa7 {+M21/29 4s} Ke4 {+M22/28
3s} 40. Kb6 {+M20/29 10s} Kd5 {+M22/25 1s} 41. Ra8 {+M18/30
13s} Kd4 {+M19/30 4s} 42. Kc6 {+M17/30 9s} Ke4 {+M18/29 2s}
43. Kc5 {+M16/28 2s} Kf4 {+M15/31 4s} 44. Kd4 {+M14/28 12s}
Kf5 {+M14/31 2s} 45. Ra6 {+M13/28 2s} Kf4 {+M13/31 3s}
46. Rf6+ {+M12/28 2s} Kg5 {+M11/32 7s} 47. Ke5 {+M11/28 2s}
Kg4 {+M9/32 4s} 48. Rf8 {+M9/28 4s} Kg3 {+M8/33 5s} 49. Ke4
{+M8/28 4s} Kg2 {+M7/34 4s} 50. Kf4 {+M7/30 3s} Kf2 {+M6/38
3s} 51. Re8 {+M6/36 4s} Kg2 {+M5/72 3s} 52. Re2+ {+M5/144
4s} Kf1 {+M4/245 1s} 53. Kf3 {+M4/245 1s} Kg1 {+M3/245 0s}
54. Re1+ {+M3/245 0s} Kh2 {+M2/245 0s} 55. Rc1 {+M2/245 0s}
Kh3 {+M1/245 0s} 56. Rh1# {+M1/245 0s} 1-0[/pgn]

What if 10... axb4+ ? This was suggested by Stockfish 5th Nov 2022. It looks drawn.


[fen]5rk1/3rpp1p/1p1p3P/3P2P1/PpP2R2/2K5/5R2/8 w - - 0 11[/fen]

Hello Gordon, I think you are probably right, I have not checked the position that you analyzed but one move later Crystal 5 KWK thinks that there is still a draw possible (There is possible Zugzwang so it is best to take an engine that could recognize that better than Stockfish.) I have been going backwards from move 16, when I come to move 11 it still seems drawn, after that, no more


[fen]2r3k1/r4p1p/3pp2P/pR1P2P1/P1P2R2/3K4/8/8 b - -[/fen]


39/71 78:57 +7.37 16...Td8 17.Tf6 Te8 18.dxe6 fxe6
19.Tb6 e5 20.Tbxd6 e4+ 21.Ke3 Tc7
22.Tc6 Tce7 23.Tb6 Tc7 24.Tfc6 Td7
25.Td6 Tc7 26.Td4 Tc5 27.Tb5 Tc7
28.Txe4 Td8 29.Td5 Tf8 (4.345.050.464) 917


[fen]2r3k1/r3pp1p/3p3P/pR1P2P1/P1P5/3K4/5R2/8 b - -[/fen]


43/73 39:01 +6.72 15...Tac7 16.Tc2 Kf8 17.Txa5 e6
18.Tb5 exd5 19.Txd5 Te8 20.a5 Te1
21.Txd6 Td1+ 22.Td2 Tg1 23.Kc3 Txg5
24.a6 Ke7 25.Kb4 Te5 26.T6d5 Te4
27.Tc5 Ta7 28.Ta5 Te1 (2.093.884.230) 894


[fen]2r2k2/r3pp1p/3p3P/pR1P2P1/P1P2R2/3K4/8/8 b - -[/fen]


42/72 49:07 +6.58 14...Kg8 15.Tf2 Tf8 16.Tg2 Tc7
17.Txa5 Tfc8 18.Tc2 e6 19.Tb5 exd5
20.Txd5 Tc6 21.Tf5 f6 22.Txf6 Tc5
23.g6 hxg6 24.Txg6+ Kh8 25.Txd6 Ta5
26.Ta2 Th5 27.Te2 Kg8 (2.576.195.176) 874


[fen]2r3k1/r3pp1p/3p3P/pR1P2P1/P1P2R2/2K5/8/8 b - -[/fen]


40/74 30:18 +6.57 13...Kf8 14.Kd3 Ke8 15.Tb2 Tac7
16.Tbf2 Tb8 17.g6 hxg6 18.h7 Tb3+
19.Kd2 Th3 20.Txf7 Txc4 21.Tf8+ Kd7
22.h8D Txh8 23.Txh8 Td4+ 24.Ke1 Txd5
25.Ta8 Tc5 26.Te2 e5 (1.600.915.032) 880


[fen]5rk1/r3pp1p/3p3P/p2P2P1/P1P2R2/2K5/1R6/8 b - -[/fen]


47/90 61:08 +5.69 12...Te8 13.Kd3 Tc8 14.Tb5 Kf8
15.Tf1 Tac7 16.Tc1 e6 17.Txa5 Ke7
18.Tb5 f6 19.gxf6+ Kxf6 20.Tb6 exd5
21.Txd6+ Kf7 22.Txd5 Tc6 23.Td7+ Kg6
24.Kd4 Kxh6 25.c5 Kg6 (3.206.385.614) 874


[fen]5rk1/r3pp1p/1p1p3P/P2P2P1/P1P2R2/2K5/5R2/8 b - -[/fen]


51/85 40:06 +0.18 11...Txa5 12.Te4 Te8 13.Tfe2 Ta7
14.T4e3 Kf8 15.Kb4 Tea8 16.Ta2 Ta5
17.Ta1 T5a7 18.Tf3 Kg8 19.Tf4 Tc8
20.Taf1 Tf8 21.T4f2 Tc7 22.Te2 Ta7
23.Tfe1 Te8 24.Te4 Kf8 (2.319.164.913) 963


All analysis from Crystal 5 KWK. Nice work from Joseph Ellis from what I can see just here! Crystal was using no tablebases, only one core. Because of going backwards also all the moves are different from Stockfish but that was probably only speedchess?

[Kooper]

The position seems drawn if continued from 10... axb4+ nor played again from the h6.

Thanks for the input.

[pepechuy]

The position seems drawn if continued from 10... axb4+ nor played again from the h6.

Thanks for the input.

Hi.

Thank you all for the analysis.
This is very interesting... at least to me, since it is from one of my games.

I must say that this is way above what I can see during a game.

Greetings.

[Eelco de Groot]

After the last update from Chrome possibly, or it was latest update of Windows, the diagrams, at least for me, do not get displayed anymore? Display of pgn is okay

[Eelco de Groot]

After the last update from Chrome possibly, or it was latest update of Windows, the diagrams, at least for me, do not get displayed anymore? Display of pgn is okay

Now they work again, and the red textbox at the top of the page has disappeared I assume the code that restores the diagrams was blocked temporarily so I saw the red textbox at the top of every page? And it was just on one computer. Everything in working order again (I hope). Eind goed al goed!