Re: What's up with this endgame?
Posted: Sat Jul 20, 2019 9:11 pm
Thanks
I doubt that this position is a win for White. Black should simply avoid gxf4 and not allow the white king to penetrate across the c-file.ChickenLogic wrote: ↑Sat Jul 20, 2019 8:17 pm [d]8/3b2k1/1p3pp1/3p1p2/3P1P2/P3P3/5KP1/5B2 b - -
At depth 100/187 SF dev finally shows +2.96 with analysis contempt on (c=24 so real eval is probably around +3.2 is my guess). So this might just be mate in N from this position.
Could this position be solved by Freezer and/or FinalGen? I think it is a suitable position: 1 minor piece vs 1 minor piece and some blocked pawns... however, the elapsed time to get the solution must be huge, as well as RAM and storage space available, because there are 7 + 7 = 14 pieces OTB.zullil wrote: ↑Sat Jul 20, 2019 9:21 pmI doubt that this position is a win for White. Black should simply avoid gxf4 and not allow the white king to penetrate across the c-file.ChickenLogic wrote: ↑Sat Jul 20, 2019 8:17 pm [d]8/3b2k1/1p3pp1/3p1p2/3P1P2/P3P3/5KP1/5B2 b - -
At depth 100/187 SF dev finally shows +2.96 with analysis contempt on (c=24 so real eval is probably around +3.2 is my guess). So this might just be mate in N from this position.
But, who knows.
Well, some forward and backward analysis suggests that I was wrong. Cfish-dev says:zullil wrote: ↑Sat Jul 20, 2019 9:21 pmI doubt that this position is a win for White. Black should simply avoid gxf4 and not allow the white king to penetrate across the c-file.ChickenLogic wrote: ↑Sat Jul 20, 2019 8:17 pm [d]8/3b2k1/1p3pp1/3p1p2/3P1P2/P3P3/5KP1/5B2 b - -
At depth 100/187 SF dev finally shows +2.96 with analysis contempt on (c=24 so real eval is probably around +3.2 is my guess). So this might just be mate in N from this position.
But, who knows.
Please, could you check the eval by playing the main line move by move ?zullil wrote: ↑Sat Jul 20, 2019 11:45 pmWell, some forward and backward analysis suggests that I was wrong. Cfish-dev says:zullil wrote: ↑Sat Jul 20, 2019 9:21 pmI doubt that this position is a win for White. Black should simply avoid gxf4 and not allow the white king to penetrate across the c-file.ChickenLogic wrote: ↑Sat Jul 20, 2019 8:17 pm [d]8/3b2k1/1p3pp1/3p1p2/3P1P2/P3P3/5KP1/5B2 b - -
At depth 100/187 SF dev finally shows +2.96 with analysis contempt on (c=24 so real eval is probably around +3.2 is my guess). So this might just be mate in N from this position.
But, who knows.
+3.84 40... Kf7 41. Ke1 Ke7 42. Kd2 Be8 43. Kc3 Kd6 44. Bd3 Ba4 45. Kb4 Bd1 46. a4 Kc6 47. Bb5+ Kb7 48. Bf1 Bh5 49. g3 g5 50. Bd3 Bg6 51. a5 Ka7 52. Bb5 Bh5 53. Bd7 Kb7 54. Bxf5 Bf3 55. Bc2 Bg2 56. Bd3 bxa5+ 57. Kxa5 Kc6 58. Bc2 Bf1 59. Ba4+ Kc7 60. Bb5 Bh3 61. Be2 Kc6 62. Ba6 Bg4 63. Bd3 Bh5 64. Bb5+ Kc7 65. Ba6 Bd1 66. Bd3 Kc6 67. Bb5+ Kb7 68. Bf1 Kc6 69. Bh3 Be2 70. Bf5 Bc4 71. Be6 Be2 72. Bf7 Bd3 73. Be8+ Kc7 74. Bh5 Kb7 75. Bd1 Kc6 76. Bg4 Be4 77. Be6 Bc2 78. Ka6 Bg6 79. Ka7 Kd6 80. Bg4 Kc7 81. Bf3 Kc6 82. Kb8 Bf5 83. Bh5 Kb6 84. Be8 Bh3 85. Bf7 gxf4 86. gxf4 Kc6 87. Be8+ Kb6 88. Bg6 Bd7 89. Bc2 Be6 90. Bb3 Kc6 91. Ba4+ Kd6 (depth 87, 0:30:47)
This is doubtful. My opponent was using some weeks for the moves, in that time he played what he believed was winning, and he was right, so if the position in the OP is a mate in something, my opponent picked it because he figured that out already, so I don't think he messed up later on.
I can confirm that backwards solving the line from CFish seems to get stuck on move 77 and Bd3 so far is the only move that does not lose. But no tablebases etc. used. 1.23 I consider a draw. 77...Bc2 would lose.Vinvin wrote: ↑Sun Jul 21, 2019 1:02 amPlease, could you check the eval by playing the main line move by move ?zullil wrote: ↑Sat Jul 20, 2019 11:45 pmWell, some forward and backward analysis suggests that I was wrong. Cfish-dev says:zullil wrote: ↑Sat Jul 20, 2019 9:21 pmI doubt that this position is a win for White. Black should simply avoid gxf4 and not allow the white king to penetrate across the c-file.ChickenLogic wrote: ↑Sat Jul 20, 2019 8:17 pm [d]8/3b2k1/1p3pp1/3p1p2/3P1P2/P3P3/5KP1/5B2 b - -
At depth 100/187 SF dev finally shows +2.96 with analysis contempt on (c=24 so real eval is probably around +3.2 is my guess). So this might just be mate in N from this position.
But, who knows.
+3.84 40... Kf7 41. Ke1 Ke7 42. Kd2 Be8 43. Kc3 Kd6 44. Bd3 Ba4 45. Kb4 Bd1 46. a4 Kc6 47. Bb5+ Kb7 48. Bf1 Bh5 49. g3 g5 50. Bd3 Bg6 51. a5 Ka7 52. Bb5 Bh5 53. Bd7 Kb7 54. Bxf5 Bf3 55. Bc2 Bg2 56. Bd3 bxa5+ 57. Kxa5 Kc6 58. Bc2 Bf1 59. Ba4+ Kc7 60. Bb5 Bh3 61. Be2 Kc6 62. Ba6 Bg4 63. Bd3 Bh5 64. Bb5+ Kc7 65. Ba6 Bd1 66. Bd3 Kc6 67. Bb5+ Kb7 68. Bf1 Kc6 69. Bh3 Be2 70. Bf5 Bc4 71. Be6 Be2 72. Bf7 Bd3 73. Be8+ Kc7 74. Bh5 Kb7 75. Bd1 Kc6 76. Bg4 Be4 77. Be6 Bc2 78. Ka6 Bg6 79. Ka7 Kd6 80. Bg4 Kc7 81. Bf3 Kc6 82. Kb8 Bf5 83. Bh5 Kb6 84. Be8 Bh3 85. Bf7 gxf4 86. gxf4 Kc6 87. Be8+ Kb6 88. Bg6 Bd7 89. Bc2 Be6 90. Bb3 Kc6 91. Ba4+ Kd6 (depth 87, 0:30:47)
I have some doubts with long lines in Stockfish. They are sometimes wrong.
In the line displayed here 77...Bc2 is losing but 77...Bd3 seems drawish.