Neverending flaws

[zullil]

[d]r2q2k1/1p1n1p1p/2pBn1p1/p1P1N1b1/P2Pp3/1P5P/1Q2NPP1/4R1K1 b - - 0 29
Houdini thinks it is more than half a pawn up, SF sees the position as perfectly equal. It is impossible, however, not to take into consideration the big assets the c5 white pawn, blocked by enemy c6, as well as the Bd6 and Ne5 represent. They all constitute space advantage, but SF somehow severely underestimates them.

The latest SF recognizes that White is better:

Code: Select all

info depth 25 seldepth 35 score cp -12 nodes 86102984 nps 7289450 time 11812 multipv 1 pv d7e5 d4e5 e4e3 e2c3 g5h6 f2e3 d8h4 b2f2 h4b4 c3d1 b4b3 e1f1 e6d8 f2f6 h6g7 f6e7 b3e6 e7e6 d8e6 d1c3 a8e8 g1f2 e6g5 f1b1 g7e5 d6e5 e8e5 b1b7 e5c5
info depth 26 currmove d7e5 currmovenumber 1

Code: Select all

info depth 45 seldepth 75 score cp -36 nodes 172493578172 nps 20372209 time 8467102 multipv 1 pv g5f6 b2c3 f6g5 e5c4 b7b6 c3c2 f7f5 e1d1 b6c5 d4c5 d8e8 e2d4 e6d4 d1d4 e4e3 c2e2 e3f2 g1f2 e8e2 f2e2 g5f6 d4d3 g8f7 e2f3 h7h5 g2g3 g6g5 d3e3 g5g4 f3g2 f6g5 e3e2 g5f6 h3h4 f7g6 e2e3 g6f7 e3e1 f7g6 e1e6 g6f7

Thank you, Louis.

I think white is even better than those 36cps.

You might be right, though SF is moving back (just a bit) toward 0:

Code: Select all

info depth 47 seldepth 75 score cp -33 nodes 218071684089 nps 20437969 time 10669929 multipv 1 pv g5f6 b2c3 f6g5 e5c4 b7b6 c3c2 f7f5 e1d1 b6c5 d4c5 d8e8 e2d4 e6d4 d1d4 e4e3 c2e2 e3f2 g1f2 e8e2 f2e2 g5f6 d4d3 g8f7 e2f3 h7h5 g2g3 f6g5 d3d1 g5f6 h3h4 a8a6 d1e1 a6a7 e1e3 a7a8 f3g2 a8a7 e3e2 a7a8 g2f3 a8a7 e2e3

[Henk]

I might post here a couple of more examples of SF lost games over time.

Congatulations to the new moderators, btw.
I hope they will not ban my activities as soon as they take charge...

Maybe if they invite Lucas Braesch for some moderators were going on a holiday.

[Lyudmil Tsvetkov]

To add just one more blockading condition: imbalances of N vs R with opposite-coloured bishops.

[d]6k1/5b2/8/3p4/2rN4/4B3/8/6K1 w - - 0 1

[Lyudmil Tsvetkov]

It is fashionable nowadays to test patches of different zero mobility pieces. If there is a piece, however, that looks ugliest with zero safe mobility, that is the rook.
Below a game of SF against Houdini, where SF quite successfully shuts in a zero mobility rook.

[pgn][PlyCount "248"]
[MLNrOfMoves "124"]
[MLFlags "100100"]
[Event "SCCT"]
[Date "2014.03.16"]
[Round "2"]
[White "Stockfish 120314 x64 1c"]
[Black "Houdini 4 x64 1c"]
[Result "0-1"]
[EventDate "2014.??.??"]
[ECO "A30"]
[TimeControl "60+1"]


{Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz 2494 MHz W=28.2 plies; 1.201kN/s; Perfect2014t.ctg B=19.3 plies; 1.612kN/s; Perfect2014t.ctg}
1. Nf3 {[%eval 0,0] [%emt 0:00:00]} 1... Nf6 {[%eval 0,0] [%emt 0:00:00]} 2. c4
{[%eval 0,0] [%emt 0:00:00]} 2... c5 {[%eval 0,0] [%emt 0:00:00]} 3. g3
{[%eval 0,0] [%emt 0:00:00]} 3... b6 {[%eval 0,0] [%emt 0:00:00]} 4. Bg2
{[%eval 0,0] [%emt 0:00:00]} 4... Bb7 {[%eval 0,0] [%emt 0:00:00]} 5. O-O
{[%eval 0,0] [%emt 0:00:00]} 5... g6 {[%eval 0,0] [%emt 0:00:00]} 6. Nc3
{[%eval 0,0] [%emt 0:00:00]} 6... Bg7 {[%eval 0,0] [%emt 0:00:00]} 7. d4
{[%eval 0,0] [%emt 0:00:00]} 7... cxd4 {[%eval 0,0] [%emt 0:00:00]} 8. Qxd4
{[%eval 0,0] [%emt 0:00:00]} 8... d6
{Both last book move [%eval 0,0] [%emt 0:00:00]} 9. Be3
{[%eval 42,18] [%emt 0:00:05]} 9... Nbd7 {[%eval 21,17] [%emt 0:00:08]} 10. Rfd1
{(Rac1) [%eval 45,20] [%emt 0:00:00]} 10... O-O {[%eval 11,17] [%emt 0:00:03]}
11. Qh4 {[%eval 49,19] [%emt 0:00:02]} 11... Nc5
{(Re8) [%eval 14,16] [%emt 0:00:01]} 12. Rac1
{(Bh6) [%eval 53,17] [%emt 0:00:02]} 12... Qd7
{(Rc8) [%eval 12,16] [%emt 0:00:04]} 13. Bh6 {(b3) [%eval 53,19] [%emt 0:00:11]}
13... Nce4 {[%eval 19,17] [%emt 0:00:06]} 14. Bh3 {[%eval 40,21] [%emt 0:00:02]}
14... Qe8 {(Qd8) [%eval 17,18] [%emt 0:00:01]} 15. Nxe4
{[%eval 42,20] [%emt 0:00:02]} 15... Bxe4 {(Nxe4) [%eval 19,17] [%emt 0:00:01]}
16. Nd4 {(a3) [%eval 70,19] [%emt 0:00:04]} 16... Rd8
{(Bb7) [%eval 21,16] [%emt 0:00:02]} 17. Bg5
{(Bxg7) [%eval 71,19] [%emt 0:00:02]} 17... Ba8
{(Bb7) [%eval 13,17] [%emt 0:00:04]} 18. b3 {[%eval 87,20] [%emt 0:00:02]} 18...
Bb7 {[%eval 15,17] [%emt 0:00:04]} 19. f3 {(Rd2) [%eval 88,20] [%emt 0:00:00]}
19... a6 {(Bc8) [%eval 23,16] [%emt 0:00:03]} 20. e4
{(Kg2) [%eval 85,19] [%emt 0:00:02]} 20... Bc8 {[%eval 17,17] [%emt 0:00:01]}
21. Bg2 {[%eval 90,18] [%emt 0:00:08]} 21... Bb7 {[%eval 19,18] [%emt 0:00:00]}
22. Nc2 {(Ne2) [%eval 80,18] [%emt 0:00:06]} 22... Qc6
{[%eval 18,16] [%emt 0:00:01]} 23. a3 {(Bh3) [%eval 68,17] [%emt 0:00:01]} 23...
a5 {[%eval 8,17] [%emt 0:00:09]} 24. Be3 {[%eval 73,19] [%emt 0:00:01]} 24...
Rfe8 {[%eval 13,18] [%emt 0:00:02]} 25. Nd4 {[%eval 71,19] [%emt 0:00:00]} 25...
Qc8 {[%eval 27,18] [%emt 0:00:01]} 26. Bh3 {(Nb5) [%eval 55,20] [%emt 0:00:02]}
26... Nd7 {[%eval 21,17] [%emt 0:00:02]} 27. Nb5 {[%eval 38,20] [%emt 0:00:04]}
27... Bf6 {[%eval 26,18] [%emt 0:00:00]} 28. Bxd7
{(Qh6) [%eval 39,20] [%emt 0:00:03]} 28... Qxd7 {[%eval -4,16] [%emt 0:00:01]}
29. Bg5 {(Qh6) [%eval 39,21] [%emt 0:00:00]} 29... Bg7
{[%eval 2,16] [%emt 0:00:04]} 30. Nc3 {[%eval 38,19] [%emt 0:00:00]} 30... Rc8
{(Bxc3) [%eval -4,15] [%emt 0:00:03]} 31. a4
{(Be3) [%eval 44,17] [%emt 0:00:02]} 31... Be5
{(f5) [%eval 10,16] [%emt 0:00:07]} 32. Nd5 {(Be3) [%eval 75,17] [%emt 0:00:02]}
32... Bxd5 {[%eval 7,15] [%emt 0:00:01]} 33. Rxd5 {[%eval 80,18] [%emt 0:00:01]}
33... Bb2 {(Qc7) [%eval 14,17] [%emt 0:00:02]} 34. Rcd1
{[%eval 61,20] [%emt 0:00:02]} 34... Ba3 {[%eval 19,18] [%emt 0:00:00]} 35. Qh6
{(Be3) [%eval 58,21] [%emt 0:00:01]} 35... Bc5+ {[%eval 19,17] [%emt 0:00:02]}
36. Kg2 {(Be3) [%eval 50,21] [%emt 0:00:00]} 36... f6
{(Qe6) [%eval 19,17] [%emt 0:00:01]} 37. Be3 {[%eval 52,20] [%emt 0:00:03]}
37... Qe6 {[%eval 16,18] [%emt 0:00:00]} 38. g4
{(R5d3) [%eval 52,20] [%emt 0:00:01]} 38... Rb8
{(Qf7) [%eval 13,16] [%emt 0:00:02]} 39. Bf2 {[%eval 56,20] [%emt 0:00:04]}
39... Qf7 {[%eval 10,18] [%emt 0:00:00]} 40. h4 {[%eval 59,20] [%emt 0:00:02]}
40... Rf8 {(Rb7) [%eval 10,17] [%emt 0:00:00]} 41. Qd2
{[%eval 63,21] [%emt 0:00:02]} 41... Rb7 {(Rfc8) [%eval 10,16] [%emt 0:00:00]}
42. h5 {(Qh6) [%eval 65,20] [%emt 0:00:01]} 42... g5
{[%eval 11,16] [%emt 0:00:01]} 43. Bd4 {(Rd3) [%eval 65,23] [%emt 0:00:00]}
43... h6 {(Rc8) [%eval 7,17] [%emt 0:00:02]} 44. Rf5
{(Bf2) [%eval 64,20] [%emt 0:00:02]} 44... Rc8
{(Rbb8) [%eval 8,17] [%emt 0:00:01]} 45. Bc3
{(Qd3) [%eval 64,20] [%emt 0:00:01]} 45... e5
{(Rd7) [%eval 10,18] [%emt 0:00:02]} 46. Qd3
{(Qd5) [%eval 77,27] [%emt 0:00:02]} 46... Kg7 {[%eval 10,18] [%emt 0:00:01]}
47. Bd2 {(Be1) [%eval 77,29] [%emt 0:00:00]} 47... Qe6
{(Qe7) [%eval 10,19] [%emt 0:00:01]} 48. Bc1
{(Be3) [%eval 77,26] [%emt 0:00:04]} 48... Rf8
{(Rd8) [%eval 10,20] [%emt 0:00:01]} 49. Be3 {[%eval 77,27] [%emt 0:00:01]}
49... Rd7 {(Rd8) [%eval 10,20] [%emt 0:00:00]} 50. Qe2
{(Qd2) [%eval 77,26] [%emt 0:00:02]} 50... Rc8
{(Rb7) [%eval 10,21] [%emt 0:00:01]} 51. Qd2
{(Qd3) [%eval 77,27] [%emt 0:00:02]} 51... Rcd8
{(Rb8) [%eval 10,21] [%emt 0:00:01]} 52. Qc1
{(Qd3) [%eval 77,28] [%emt 0:00:02]} 52... Qe7
{(Kg8) [%eval 10,19] [%emt 0:00:01]} 53. Qc3
{(Qd2) [%eval 77,28] [%emt 0:00:01]} 53... Qe6
{(Rc7) [%eval 10,21] [%emt 0:00:01]} 54. Rd5
{(Qc1) [%eval 77,29] [%emt 0:00:02]} 54... Rc8
{(Qe7) [%eval 10,19] [%emt 0:00:01]} 55. Qd2
{(Rd1) [%eval 77,28] [%emt 0:00:01]} 55... Rb8
{(Rcd8) [%eval 10,19] [%emt 0:00:01]} 56. Bg1
{(Qc3) [%eval 77,28] [%emt 0:00:02]} 56... Qe7
{(Rbd8) [%eval 10,19] [%emt 0:00:01]} 57. Bf2
{(Qc3) [%eval 77,29] [%emt 0:00:01]} 57... Kh7
{(Rbd8) [%eval 10,19] [%emt 0:00:01]} 58. Qc1
{(Be3) [%eval 77,27] [%emt 0:00:01]} 58... Rbd8
{(Kg7) [%eval 10,19] [%emt 0:00:01]} 59. Rd1 {[%eval 77,29] [%emt 0:00:01]}
59... Qe6 {(Kg8) [%eval 10,20] [%emt 0:00:00]} 60. Qc3
{(Qd2) [%eval 77,28] [%emt 0:00:01]} 60... Qf7
{(Qe7) [%eval 10,20] [%emt 0:00:01]} 61. Be3
{(Qd2) [%eval 77,27] [%emt 0:00:01]} 61... Kg8
{(Qe7) [%eval 10,20] [%emt 0:00:01]} 62. Qd2
{(Qd3) [%eval 77,27] [%emt 0:00:01]} 62... Kg7
{(Qe7) [%eval 10,21] [%emt 0:00:02]} 63. Qe2
{(Qd3) [%eval 77,28] [%emt 0:00:01]} 63... Qe7 {[%eval 10,21] [%emt 0:00:01]}
64. Rd2 {(Qd3) [%eval 77,29] [%emt 0:00:00]} 64... Qe6
{(Rc7) [%eval 10,21] [%emt 0:00:01]} 65. Rd5
{(Rd1) [%eval 77,30] [%emt 0:00:01]} 65... Kh7
{(Qf7) [%eval 10,21] [%emt 0:00:02]} 66. Qe1
{(Rd1) [%eval 77,31] [%emt 0:00:01]} 66... Qe7
{(Kg7) [%eval 10,20] [%emt 0:00:01]} 67. Bf2
{(Qe2) [%eval 77,29] [%emt 0:00:01]} 67... Kh8
{(Kg7) [%eval 10,20] [%emt 0:00:01]} 68. Rd1 {[%eval 77,29] [%emt 0:00:01]}
68... Kg7 {[%eval 10,21] [%emt 0:00:00]} 69. Be3
{(Qd2) [%eval 77,30] [%emt 0:00:01]} 69... Rc7 {[%eval 10,20] [%emt 0:00:01]}
70. Rd5 {(Qd2) [%eval 77,31] [%emt 0:00:00]} 70... Rb7
{(Rcc8) [%eval 10,19] [%emt 0:00:01]} 71. Bf2
{(Qe2) [%eval 77,29] [%emt 0:00:01]} 71... Rbb8
{(Rc7) [%eval 10,20] [%emt 0:00:01]} 72. Qc1
{(Rd1) [%eval 77,30] [%emt 0:00:01]} 72... Qa7
{(Rbc8) [%eval 10,18] [%emt 0:00:01]} 73. Qd2
{(Qc2) [%eval 77,30] [%emt 0:00:01]} 73... Qd7
{(Qe7) [%eval 10,19] [%emt 0:00:01]} 74. Bg3
{(Qe2) [%eval 77,28] [%emt 0:00:01]} 74... Qe7 {[%eval 7,18] [%emt 0:00:01]} 75.
Qd1 {(Bf2) [%eval 77,31] [%emt 0:00:00]} 75... Re8
{(Rbc8) [%eval 6,19] [%emt 0:00:01]} 76. Qc1
{(Bf2) [%eval 77,31] [%emt 0:00:01]} 76... Rbd8
{(Red8) [%eval 7,18] [%emt 0:00:01]} 77. Qd2
{(Rd1) [%eval 77,30] [%emt 0:00:01]} 77... Rd7
{(Rc8) [%eval 5,19] [%emt 0:00:02]} 78. Bf2 {[%eval 77,32] [%emt 0:00:01]} 78...
Red8 {[%eval 4,19] [%emt 0:00:00]} 79. Be3 {(Qe2) [%eval 77,32] [%emt 0:00:01]}
79... Qf7 {(Rb7) [%eval 3,19] [%emt 0:00:02]} 80. Qc1
{(Qe2) [%eval 77,29] [%emt 0:00:02]} 80... Qf8
{(Qe7) [%eval 3,18] [%emt 0:00:02]} 81. Bd2 {(Rd1) [%eval 77,29] [%emt 0:00:01]}
81... Qe7 {[%eval 4,18] [%emt 0:00:01]} 82. Qc3
{(Be3) [%eval 77,30] [%emt 0:00:01]} 82... Rb7
{(Rc8) [%eval 2,18] [%emt 0:00:02]} 83. Be3 {(Be1) [%eval 77,31] [%emt 0:00:01]}
83... Kh7 {(Rbb8) [%eval 3,19] [%emt 0:00:02]} 84. Qd3
{(Rd1) [%eval 77,28] [%emt 0:00:01]} 84... Kg8 {[%eval 2,18] [%emt 0:00:02]} 85.
Qd2 {(Qe2) [%eval 77,33] [%emt 0:00:00]} 85... Rbb8
{(Kg7) [%eval 2,18] [%emt 0:00:01]} 86. Qc1 {(Qe2) [%eval 77,29] [%emt 0:00:01]}
86... Kh8 {(Rbc8) [%eval -1,18] [%emt 0:00:02]} 87. Qe1
{(Rd1) [%eval 77,29] [%emt 0:00:01]} 87... Kg7
{(Rbc8) [%eval 5,17] [%emt 0:00:02]} 88. Qc1
{(Rd1) [%eval 77,29] [%emt 0:00:01]} 88... Qd7
{(Rbc8) [%eval 6,17] [%emt 0:00:04]} 89. Qc3
{(Rd1) [%eval 35534,23] [%emt 0:00:06]} 89... Bb4
{(Ra8) [%eval 10,18] [%emt 0:00:03]} 90. Qc2 {(Qc1) [%eval 0,22] [%emt 0:00:02]}
90... Bc5 {[%eval 21,15] [%emt 0:00:03]} 91. Bxc5
{(Bf2) [%eval 0,30] [%emt 0:00:00]} 91... bxc5 {[%eval -9,9] [%emt 0:00:00]} 92.
Rd1 {(Kg3) [%eval 0,24] [%emt 0:00:01]} 92... Rb4
{[%eval -46,16] [%emt 0:00:01]} 93. Qd3 {[%eval 0,28] [%emt 0:00:00]} 93... Qb7
{(Qe7) [%eval -97,17] [%emt 0:00:01]} 94. Rb1 {[%eval -8,28] [%emt 0:00:01]}
94... Rd7 {(Qe7) [%eval -70,17] [%emt 0:00:01]} 95. Kg3
{(Kh3) [%eval -33,22] [%emt 0:00:03]} 95... Qb8 {[%eval -114,17] [%emt 0:00:01]}
96. Qd1 {(Qd5) [%eval 35534,22] [%emt 0:00:02]} 96... Rdb7
{[%eval -129,16] [%emt 0:00:01]} 97. Qd2 {(Qe1) [%eval -160,21] [%emt 0:00:01]}
97... Rxb3 {(Rxc4) [%eval -187,15] [%emt 0:00:01]} 98. Rxb3
{(Rd1) [%eval 35534,20] [%emt 0:00:02]} 98... Rxb3
{[%eval -223,15] [%emt 0:00:00]} 99. Kh3 {(Qxa5) [%eval -319,22] [%emt 0:00:01]}
99... Kf7 {(Rb1) [%eval -244,18] [%emt 0:00:01]} 100. Qxa5
{[%eval 35534,30] [%emt 0:00:02]} 100... Ke7
{(Rb1) [%eval -308,19] [%emt 0:00:00]} 101. Qa6
{(Kg3) [%eval -366,26] [%emt 0:00:01]} 101... Rb6
{[%eval -307,17] [%emt 0:00:00]} 102. Qa5 {[%eval -432,26] [%emt 0:00:01]}
102... Rb1 {[%eval -353,20] [%emt 0:00:00]} 103. Kg3
{[%eval -498,23] [%emt 0:00:01]} 103... Qb7 {[%eval -401,18] [%emt 0:00:00]}
104. Kh3 {[%eval -515,23] [%emt 0:00:00]} 104... Rb4
{[%eval -423,17] [%emt 0:00:00]} 105. Kg3 {[%eval -581,23] [%emt 0:00:02]}
105... Rxc4 {[%eval -584,15] [%emt 0:00:00]} 106. Qb5
{[%eval 35534,23] [%emt 0:00:01]} 106... Qxb5 {[%eval -1151,16] [%emt 0:00:00]}
107. axb5 {[%eval -818,30] [%emt 0:00:01]} 107... Rc2
{[%eval -1120,19] [%emt 0:00:01]} 108. Kh3 {(f4) [%eval -988,25] [%emt 0:00:00]}
108... Rb2 {[%eval -1103,14] [%emt 0:00:00]} 109. Kg3
{[%eval -1098,27] [%emt 0:00:01]} 109... Rxb5 {[%eval -1348,18] [%emt 0:00:00]}
110. Kf2 {(Kh3) [%eval -1166,28] [%emt 0:00:02]} 110... Rb4
{(Rb2+) [%eval -2027,17] [%emt 0:00:01]} 111. Ke2
{(f4) [%eval -1193,28] [%emt 0:00:01]} 111... Rd4
{(c4) [%eval -2300,18] [%emt 0:00:00]} 112. f4
{(Kf2) [%eval -2097,20] [%emt 0:00:01]} 112... gxf4
{(Rxe4+) [%eval -32750,19] [%emt 0:00:00]} 113. Kf3
{(g5) [%eval 35534,24] [%emt 0:00:01]} 113... c4
{[%eval -32752,20] [%emt 0:00:00]} 114. g5 {[%eval -13793,25] [%emt 0:00:01]}
114... fxg5 {[%eval -32753,20] [%emt 0:00:00]} 115. Kg4
{[%eval -32752,19] [%emt 0:00:01]} 115... c3 {[%eval -32757,22] [%emt 0:00:00]}
116. Rxg5 {[%eval -32753,19] [%emt 0:00:01]} 116... hxg5
{[%eval -32758,23] [%emt 0:00:00]} 117. h6 {[%eval -32759,20] [%emt 0:00:01]}
117... Rd1 {[%eval -32759,24] [%emt 0:00:01]} 118. h7
{[%eval -32760,24] [%emt 0:00:00]} 118... Rh1 {[%eval -32760,25] [%emt 0:00:00]}
119. h8Q {(Kxg5) [%eval -32761,36] [%emt 0:00:01]} 119... Rxh8
{[%eval -32761,21] [%emt 0:00:00]} 120. Kf3 {[%eval -32762,58] [%emt 0:00:01]}
120... c2 {[%eval -32762,44] [%emt 0:00:00]} 121. Ke2
{(Kg4) [%eval -32763,120] [%emt 0:00:00]} 121... c1Q
{[%eval -32763,17] [%emt 0:00:00]} 122. Kf3 {[%eval -32764,120] [%emt 0:00:00]}
122... Qd1+ {[%eval -32764,41] [%emt 0:00:00]} 123. Kg2
{[%eval -32765,120] [%emt 0:00:00]} 123... Qh1+
{[%eval -32765,99] [%emt 0:00:00]} 124. Kf2 {[%eval -32766,120] [%emt 0:00:00]}
124... Rh2# {[%eval -32766,99] [%emt 0:00:00]} 0-1
[/pgn]

[d]2r3k1/1r2pq2/1p1p1p1p/p1b2RpP/P1PBP1P1/1P3P2/3Q2K1/3R4 w - - 0 45
Here SF plays 45.Bc3 with 70cps advantage.

[d]2r3k1/1r3q2/1p1p1p1p/p1b1pRpP/P1P1P1P1/1PB2P2/3Q2K1/3R4 w - - 0 46
And Houdini replies 45.e7-e5, shuttinh in the white rook on f5 for the rest of the meaningful game with zero safe mobility. Look at that rook - it is both ugly and funny. There is nothing uglier than a zero mobility rook in the center.

[d]1r1r4/3q2k1/1p1p1p1p/p1bRpRpP/P1P1P1P1/1P2BP2/2Q3K1/8 w - - 0 91
The game is still drawn because of the blocked position, but here SF plays 91.Bc5, exchanging the bishops, after which white is lost.

[d]1q6/5k2/3p1p1p/p1p1pRpP/P1P1P1P1/1r3P1K/3Q4/8 w - - 0 100
Mate will follow shortly, it is Q+R vs Q.

In light of the above, and because of being fashionable, it seems reasonable to penalise a zero mobility rook. My penalty would be just a bit lower than that for queen on an edge file. However, in sharp distinction to the minor pieces and the queen, that are penalised when placed on the edge of the board, the rook is most vulnerable in the center.
That is why, if I were to penalise a zero mobility rook, I would do so only for the area comprised within the a3-h3-h6-a6 squares, i.e. for all files from rank 3 to rank 6. Zero mobility rooks on ranks 1 and 2 are often a very natural phenomenon, while rooks on the 7th and 8th, when available there, are tactically inclined and so no good for generalisation.

But even better suggestion would be to do a single zero mobility patch for all pieces, specifying penalties for the specific pieces with specific application areas. As zero mobility pieces on their own are a relatively rare phenomenon, a patch for all pieces significantly raises the chances of success.

What do you think of the f5 rook?
Output, comments very much appreciated. (hey, write a single reply, otherwise my thread will be uglier than a zero mobility rook)

[peter]

Engines are known for not understanding blockade,

Well, Lyudmil, as I just said in my last post in the thread about the very difficult position.
Engine's output-evals should show every strong or weak progress following the plies of the variants, and they normally do so, if you stick to the relations of the numeric evals' heights, even if the absolute numbers differ widely from engine to engine.
This relation between an output- eval at the end to the one at the start of a variant is the higher the higher the dynamics of the position is.
So an eval even meaning a winning advantage already in a certain position shows less progress if it climbs only little more over the course of the plies than a low starting one climbing quickly.
It's the gradient of the evals' progress related to the numbers of plies to be judged.
And the fortress shows a very special pattern of that gradient, as we know. It's the typically stuck eval, there's no progress in the evals' heights over the plies.
If human players analyzing with engines see that at once, why doesn't the engine itself do so, getting information out of that to evaluate the positions in a different way, if there isn't any progress of the evals' heights to be counted?
Maybe it's a naive question to a programmer, isn't it,

[Lyudmil Tsvetkov]

And now one example of a zero mobility bishop.

[pgn][PlyCount "153"]
[MLNrOfMoves "76"]
[MLFlags "100100"]
[Event "SCCT"]
[Date "2014.03.16"]
[Round "23"]
[White "Houdini 4 x64 1c"]
[Black "Stockfish 120314 x64 1c"]
[Result "1-0"]
[EventDate "2014.??.??"]
[ECO "D46"]
[TimeControl "60+1"]


{Intel(R) Core(TM) i5-3210M CPU @ 2.50GHz 2494 MHz W=23.2 plies; 1.929kN/s; Perfect2014t.ctg B=29.6 plies; 1.328kN/s; Perfect2014t.ctg}
1. Nf3 {[%eval 0,0] [%emt 0:00:00]} 1... Nf6 {[%eval 0,0] [%emt 0:00:00]} 2. d4
{[%eval 0,0] [%emt 0:00:00]} 2... e6 {[%eval 0,0] [%emt 0:00:00]} 3. c4
{[%eval 0,0] [%emt 0:00:00]} 3... d5 {[%eval 0,0] [%emt 0:00:00]} 4. Nc3
{[%eval 0,0] [%emt 0:00:00]} 4... c6 {[%eval 0,0] [%emt 0:00:00]} 5. e3
{[%eval 0,0] [%emt 0:00:00]} 5... Nbd7 {[%eval 0,0] [%emt 0:00:00]} 6. Qc2
{[%eval 0,0] [%emt 0:00:00]} 6... Bd6 {[%eval 0,0] [%emt 0:00:00]} 7. Bd3
{[%eval 0,0] [%emt 0:00:00]} 7... O-O {[%eval 0,0] [%emt 0:00:00]} 8. O-O
{[%eval 0,0] [%emt 0:00:00]} 8... dxc4 {[%eval 0,0] [%emt 0:00:00]} 9. Bxc4
{[%eval 0,0] [%emt 0:00:00]} 9... b5
{Both last book move [%eval 0,0] [%emt 0:00:00]} 10. Be2
{[%eval 43,17] [%emt 0:00:05]} 10... Bb7 {(b4) [%eval 13,18] [%emt 0:00:03]} 11.
a3 {[%eval 33,15] [%emt 0:00:05]} 11... a6 {(a5) [%eval -2,19] [%emt 0:00:00]}
12. b4 {(e4) [%eval 35,15] [%emt 0:00:05]} 12... a5
{[%eval -23,18] [%emt 0:00:03]} 13. Rb1 {[%eval 32,16] [%emt 0:00:00]} 13... Qe7
{(axb4) [%eval -16,19] [%emt 0:00:03]} 14. Qb3
{(Bd2) [%eval 38,16] [%emt 0:00:02]} 14... Rfd8
{(e5) [%eval -20,17] [%emt 0:00:02]} 15. Rd1 {[%eval 18,16] [%emt 0:00:05]}
15... e5 {(axb4) [%eval -26,18] [%emt 0:00:00]} 16. dxe5
{(bxa5) [%eval 17,15] [%emt 0:00:02]} 16... Nxe5 {[%eval 0,17] [%emt 0:00:03]}
17. Nd4 {[%eval 24,16] [%emt 0:00:00]} 17... Neg4
{(Bc7) [%eval 0,19] [%emt 0:00:03]} 18. h3 {[%eval 48,14] [%emt 0:00:03]} 18...
Bh2+ {[%eval -8,19] [%emt 0:00:00]} 19. Kf1 {[%eval 38,15] [%emt 0:00:03]} 19...
axb4 {[%eval -8,18] [%emt 0:00:05]} 20. axb4 {[%eval 35,15] [%emt 0:00:00]}
20... Ne5 {[%eval 23,19] [%emt 0:00:04]} 21. Qc2 {[%eval 55,15] [%emt 0:00:00]}
21... g6 {(h5) [%eval 0,19] [%emt 0:00:09]} 22. g3
{[%eval 79,15] [%emt 0:00:03]} 22... Rdc8 {(Nc4) [%eval 0,19] [%emt 0:00:00]}
23. Nb3 {(Rb2) [%eval 57,16] [%emt 0:00:05]} 23... Ned7
{(Qxb4) [%eval 0,18] [%emt 0:00:04]} 24. Na5
{(Bf3) [%eval 105,15] [%emt 0:00:03]} 24... c5 {[%eval 137,17] [%emt 0:00:02]}
25. Nxb7 {[%eval 88,16] [%emt 0:00:01]} 25... cxb4
{[%eval 163,18] [%emt 0:00:02]} 26. Nd6 {[%eval 87,17] [%emt 0:00:00]} 26...
Rxc3 {[%eval 170,19] [%emt 0:00:02]} 27. Qd2 {[%eval 119,17] [%emt 0:00:03]}
27... Qe5 {(Qe6) [%eval 158,20] [%emt 0:00:08]} 28. Rxb4
{(Bf3) [%eval 252,14] [%emt 0:00:02]} 28... Qc5
{(Bxg3) [%eval 249,19] [%emt 0:00:04]} 29. Rxb5
{(Bb2) [%eval 175,16] [%emt 0:00:03]} 29... Qc6 {[%eval 171,21] [%emt 0:00:02]}
30. e4 {[%eval 183,17] [%emt 0:00:00]} 30... Nxe4
{[%eval 177,23] [%emt 0:00:03]} 31. Nxe4 {[%eval 191,18] [%emt 0:00:00]} 31...
Qxe4 {[%eval 177,24] [%emt 0:00:01]} 32. Qd5 {[%eval 174,18] [%emt 0:00:00]}
32... Nf6 {[%eval 185,24] [%emt 0:00:07]} 33. Qxe4
{[%eval 205,20] [%emt 0:00:00]} 33... Nxe4 {[%eval 182,25] [%emt 0:00:01]} 34.
Bd3 {(Kg2) [%eval 171,20] [%emt 0:00:00]} 34... Nxf2
{(Rd8) [%eval 190,23] [%emt 0:00:02]} 35. Kxf2 {[%eval 227,16] [%emt 0:00:01]}
35... Bxg3+ {[%eval 236,25] [%emt 0:00:03]} 36. Kxg3
{[%eval 236,21] [%emt 0:00:00]} 36... Rd8 {[%eval 236,27] [%emt 0:00:01]} 37.
Bh6 {(Bb2) [%eval 233,21] [%emt 0:00:00]} 37... Rdxd3+
{(Rcxd3+) [%eval 236,27] [%emt 0:00:05]} 38. Rxd3
{[%eval 244,20] [%emt 0:00:01]} 38... Rxd3+ {[%eval 269,28] [%emt 0:00:03]} 39.
Kg2 {[%eval 249,24] [%emt 0:00:00]} 39... Rd8 {[%eval 240,29] [%emt 0:00:03]}
40. Rb7 {[%eval 260,23] [%emt 0:00:00]} 40... Rc8
{(Re8) [%eval 275,30] [%emt 0:00:03]} 41. Kf3 {[%eval 269,23] [%emt 0:00:02]}
41... Ra8 {(Re8) [%eval 275,30] [%emt 0:00:00]} 42. Ke4
{(Kg3) [%eval 269,24] [%emt 0:00:02]} 42... f6
{(Re8+) [%eval 277,27] [%emt 0:00:02]} 43. Kd5 {[%eval 294,21] [%emt 0:00:02]}
43... f5 {[%eval 277,28] [%emt 0:00:00]} 44. Ke6
{(Ke5) [%eval 314,21] [%emt 0:00:04]} 44... Ra6+ {[%eval 290,26] [%emt 0:00:02]}
45. Ke7 {(Ke5) [%eval 320,21] [%emt 0:00:00]} 45... Ra8
{[%eval 290,27] [%emt 0:00:02]} 46. Rd7 {(Kd6) [%eval 337,21] [%emt 0:00:01]}
46... g5 {[%eval 345,22] [%emt 0:00:05]} 47. Bxg5
{[%eval 329,21] [%emt 0:00:00]} 47... Kg7 {[%eval 352,22] [%emt 0:00:01]} 48.
Rd6 {[%eval 331,21] [%emt 0:00:01]} 48... Ra7+ {[%eval 352,21] [%emt 0:00:00]}
49. Ke6 {[%eval 332,22] [%emt 0:00:02]} 49... Ra3
{(Ra5) [%eval 354,24] [%emt 0:00:00]} 50. h4 {[%eval 330,21] [%emt 0:00:02]}
50... h6 {[%eval 360,24] [%emt 0:00:00]} 51. Bd8 {[%eval 371,20] [%emt 0:00:03]}
51... Kg6 {[%eval 370,27] [%emt 0:00:00]} 52. Ke5+
{[%eval 403,20] [%emt 0:00:03]} 52... Kh5 {[%eval 398,26] [%emt 0:00:02]} 53.
Kxf5 {[%eval 405,21] [%emt 0:00:00]} 53... Rh3
{(Rf3+) [%eval 417,24] [%emt 0:00:03]} 54. Ke6
{(Bf6) [%eval 430,20] [%emt 0:00:02]} 54... Kg6 {[%eval 424,24] [%emt 0:00:01]}
55. Rd5 {(Ke5+) [%eval 438,20] [%emt 0:00:02]} 55... Rh1
{[%eval 430,21] [%emt 0:00:02]} 56. Kd7 {[%eval 445,20] [%emt 0:00:00]} 56...
Kf7 {[%eval 450,24] [%emt 0:00:03]} 57. h5 {[%eval 467,22] [%emt 0:00:00]} 57...
Rf1 {(Rb1) [%eval 465,24] [%emt 0:00:01]} 58. Bb6
{(Rd6) [%eval 507,20] [%emt 0:00:02]} 58... Kf6
{(Re1) [%eval 481,22] [%emt 0:00:01]} 59. Bd4+ {[%eval 536,21] [%emt 0:00:02]}
59... Kf7 {[%eval 1572,26] [%emt 0:00:00]} 60. Re5
{[%eval 652,21] [%emt 0:00:01]} 60... Rb1
{(Rd1) [%eval 35534,36] [%emt 0:00:00]} 61. Rf5+ {[%eval 734,17] [%emt 0:00:00]}
61... Kg8 {[%eval 6137,33] [%emt 0:00:00]} 62. Ke6
{[%eval 734,17] [%emt 0:00:00]} 62... Rb8 {(Rb7) [%eval 7057,36] [%emt 0:00:02]}
63. Rf6 {[%eval 911,18] [%emt 0:00:01]} 63... Re8+
{[%eval 14188,36] [%emt 0:00:02]} 64. Kf5 {[%eval 994,22] [%emt 0:00:00]} 64...
Re2 {(Kh7) [%eval 14830,32] [%emt 0:00:02]} 65. Rxh6
{(Be5) [%eval 1472,16] [%emt 0:00:01]} 65... Re1
{(Kf8) [%eval 32724,21] [%emt 0:00:01]} 66. Be5
{(Re6) [%eval 32752,21] [%emt 0:00:01]} 66... Rb1
{[%eval 12756,25] [%emt 0:00:01]} 67. Rh8+
{(Rg6+) [%eval 32753,22] [%emt 0:00:00]} 67... Kf7
{[%eval 539,1] [%emt 0:00:00]} 68. Rh7+ {[%eval 32754,21] [%emt 0:00:00]} 68...
Kg8 {[%eval 32757,23] [%emt 0:00:01]} 69. Rg7+ {[%eval 32758,24] [%emt 0:00:00]}
69... Kf8 {[%eval 32758,24] [%emt 0:00:01]} 70. Ra7
{(h6) [%eval 32759,26] [%emt 0:00:00]} 70... Kg8
{[%eval 32760,23] [%emt 0:00:01]} 71. h6 {[%eval 32760,27] [%emt 0:00:00]} 71...
Rf1+ {(Rh1) [%eval 32761,33] [%emt 0:00:01]} 72. Ke6
{[%eval 32761,21] [%emt 0:00:00]} 72... Rf7 {[%eval 32762,54] [%emt 0:00:01]}
73. h7+ {[%eval 32762,48] [%emt 0:00:00]} 73... Kxh7
{[%eval 32763,94] [%emt 0:00:01]} 74. Rxf7+ {[%eval 32763,99] [%emt 0:00:00]}
74... Kg6 {[%eval 32764,120] [%emt 0:00:00]} 75. Bf4
{[%eval 32764,99] [%emt 0:00:00]} 75... Kh5 {[%eval 32765,120] [%emt 0:00:00]}
76. Kf5 {[%eval 32765,98] [%emt 0:00:10]} 76... Kh4
{[%eval 32766,120] [%emt 0:00:00]} 77. Rh7# {[%eval 32766,99] [%emt 0:00:00]}
1-0
[/pgn]

[d]r2r2k1/1b2qppp/2pb1n2/pp6/1P1N2n1/PQN1P2P/4BPP1/1RBR2K1 b - - 0 18
SF playing now 18...Bh2, seeing black advantage.

[d]r2r2k1/1b2qp1p/2p2np1/1p2n3/1P1N4/2N1P1PP/2Q1BP1b/1RBR1K2 b - - 0 22
The shut-in zero safe mobility bishop on h2 looks comical. SF already sees the danger, but its score is very unrealistic - only 20cps white edge. Houdini thinks white is almost a full pawn up.

[d]r5k1/5p1p/6p1/1R6/8/2rB2bP/5K2/2BR4 w - - 0 36
The bishop has to sacrifice itself, but black is already fully lost.

I think the penalty for a zero safe mobility bishop should be comparable to that of the knight, maybe a bit higher. Possible area where the penalty should be considered are the edge a and h files, as well as the 1st rank. It does not make sense to include the 8th rank, as bishops there are rare and never bad.

[Lyudmil Tsvetkov]

Engines are known for not understanding blockade,

Well, Lyudmil, as I just said in my last post in the thread about the very difficult position.
Engine's output-evals should show every strong or weak progress following the plies of the variants, and they normally do so, if you stick to the relations of the numeric evals' heights, even if the absolute numbers differ widely from engine to engine.
This relation between an output- eval at the end to the one at the start of a variant is the higher the higher the dynamics of the position is.
So an eval even meaning a winning advantage already in a certain position shows less progress if it climbs only little more over the course of the plies than a low starting one climbing quickly.
It's the gradient of the evals' progress related to the numbers of plies to be judged.
And the fortress shows a very special pattern of that gradient, as we know. It's the typically stuck eval, there's no progress in the evals' heights over the plies.
If human players analyzing with engines see that at once, why doesn't the engine itself do so, getting information out of that to evaluate the positions in a different way, if there isn't any progress of the evals' heights to be counted?
Maybe it's a naive question to a programmer, isn't it,

Too philosophic, too scientific for me, Peter.

For me, engines do not see blockade because they do not have the appropriate eval algorithm, they evaluate center, isolated pawns, rooks on open files, etc., all good and working eval terms, but that is not sufficient for a top engine. You have to go beyond, not only in search, but also in eval.

I think the eval algorithm I proposed about implementing blockade by knights of enemy passers (the most practical kind of blockade) is an accurate one with good implementation chances. You always need to specify in order to be successful. You can not go about saying that any knight blocking an enemy passer deserves a bonus, that is simply not true and is not going to work. You need to specify. I very much hope that someone tests the approach suggested, as blockade is a very important positional element.

Those are the real deep positional terms that scale well at LTC: imbalances, blockade, treating of closed positions. I would pay them a special attention.

[zullil]

[d]1r1r4/3q2k1/1p1p1p1p/p1bRpRpP/P1P1P1P1/1P2BP2/2Q3K1/8 w - - 0 91
The game is still drawn because of the blocked position, but here SF plays 91.Bc5, exchanging the bishops, after which white is lost.

The latest SF never considers playing Bxc5, even at low depths:

Code: Select all

Searching: 1r1r4/3q2k1/1p1p1p1p/p1bRpRpP/P1P1P1P1/1P2BP2/2Q3K1/8 w - - 0 91
infinite: 0 ponder: 0 time: 0 increment: 0 moves to go: 0

 1   +0.83   00:00     197  Qd3 
 2   +0.86   00:00     914  Qd3 Rbc8 
 3   +0.71   00:00    1388  Qd3 Rbc8 Qe2 
 4   +0.74   00:00    1873  Qd3 Rbc8 Qe2 Qf7 
 5   +0.74   00:00    2611  Qd3 Bxe3 Qxe3 Qf7 Qd2 
 6   +0.74   00:00    5401  Qd3 Rbc8 Bxc5 Rxc5 Qd2 Rxd5 Qxd5 
 7   +0.69   00:00   11137  Qd2 Rbc8 Bxc5 Rxc5 Qd3 Qe7 Qd2 Rxd5 Qxd5 
 8   +0.66   00:00   28101  Qc3 Qe7 Qd2 Rbc8 Bxc5 dxc5 Qe3 Kg8 
 9   +0.65   00:00   33290  Qc3 Qe7 Qd2 Rbc8 Bxc5 dxc5 Qe3 Qf7 Qc1 Qe8 Qd1 
10   +0.65   00:00   36947  Qc3 Qe7 Qd2 Rbc8 Bxc5 dxc5 Qe3 Qf7 Qc1 Qe8 Qd1 
11   +0.64   00:00  105831  Qc3 Qe7 Qd2 Qd7 Qe1 Qe7 Bd2 Qf7 Bc3 Rbc8 Qd2 Qe7 
12   +0.64   00:00  114578  Qc3 Qe7 Qd2 Qd7 Qe1 Qe7 Bd2 Rbc8 Bc3 Re8 Qd2 Qf7 
13   +0.64   00:00  177224  Qc3 Qe7 Qd2 Qd7 Qe1 Qe7 Bd2 Rbc8 Qc1 Re8 Be3 Red8 
                            Qd2 Rb8 Bf2 Qd7 Bg3 Qe7 Qc1 Rbc8 Rd1 Bd4 
14   +0.64   00:00  199659  Qc3 Qe7 Qd2 Qd7 Qe1 Qe7 Qc1 Qf7 Bd2 Re8 Bc3 Rbc8 
                            Bb2 Kg8 
15   +0.65   00:00  472228  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qd2 Rbb8 Bf2 
16   +0.65   00:00  519775  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qd2 Rbb8 Bf2 
17   +0.65   00:01  660610  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qd2 Kg8 Qd3 Kg7 Qd2 
18   +0.65   00:01  835561  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qd2 Kg8 Qc3 Kg7 
19   +0.65   00:01   1071K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qd2 Kg8 Qc3 Kg7 
20   +0.65   00:01   1219K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rcc8 
                            Rd1 Qe8 Qd2 Qe7 Bf2 Qc7 Bg3 Qe7 Bf2 
21   +0.65   00:01   1434K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rcc8 
                            Rd1 Qe8 Rh1 Qf7 Qd2 Qe8 Qc1 Qe7 Bf2 Qf7 Bg3 Kh8 
22   +0.65   00:02   1888K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bd2 Rbc8 Bc3 Qf7 Rd1 Re8 Qd2 Rc7 Rh1 Kh8 
                            Rd1 Rec8 
23   +0.65   00:02   2351K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bg1 Bxg1 Kxg1 Rbc8 Qd2 Rc5 Rd3 Rcc8 Kg2 
                            Kg8 Qe3 
24   +0.65   00:02   2800K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Qc3 Ra8 Rd1 Rac8 Be3 Qe8 
                            Rh1 Qf7 Qd2 Qe8 Qc1 Qe7 Rd1 Qf7 Qc3 Qe8 
25   +0.65   00:02   3231K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Qc3 Ra8 Rd1 Rac8 Be3 Qe8 
                            Rh1 Qf7 Qd2 Qe8 Qc1 Qe7 Rd1 Qf7 Qd2 Qc7 Rh1 Qf7 Bf2 
                            Kg8 Rd1 Qe7 Qc1 Kh8 Qd2 Kg7 Be3 Qc7 
26   +0.65   00:03   3813K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Qc3 Ra8 Rd1 Rac8 Be3 Qe8 
                            Rh1 Qf7 Qd2 Qe8 Qc1 Qe7 Rd1 Qf7 Qd2 Qe7 Qc1 
27   +0.65   00:03   4511K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Qc1 
28   +0.65   00:03   5410K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Be3 Ra8 Qe2 Rab8 
                            Rd1 Rbc8 Qd2 Kg8 Bf2 Kg7 Be3 
29   +0.65   00:04   6577K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Be3 Ra8 Bf2 Rac8 
30   +0.65   00:04   8300K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Be3 Ra8 Qd3 Rac8 
                            Qe2 Re8 Rd1 Qc7 Qd2 Red8 Bf2 Qe7 Be3 Rb8 Bf2 Qc7 
                            Bg3 Rbc8 Ra1 Qf7 Rh1 Qe7 Qd5 Kh8 
31   +0.65   00:05  10656K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Bf2 
32   +0.65   00:05  13268K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Be3 Qc7 Qd3 Qe7 
                            Qe2 Rb8 Rd1 Rbc8 Qd2 Ra8 Qd3 Rac8 Rh1 Qf7 Qd2 Qc7 
                            Qc1 Qe7 Rd1 Qf7 Bf2 Qe7 Qd2 Qe8 Rh1 Qe7 Be3 Qf7 Bf2 
                            Kg8 Rd1 Qe7 Be3 Kg7 Qc3 Qe8 Rd5 Rb8 Qd2 Qe7 Qd3 
                            Rbc8 
33   +0.65   00:06  17128K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Be3 Rb8 Qe2 Qf7 
                            Rd1 Rbc8 Bf2 Qa7 Be3 Qf7 
34   +0.65   00:06  24843K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Rb8 Bg1 Rbc8 Be3 Ra8 Qe2 Rab8 
                            Rd1 Rbc8 Qd2 Kg8 Rh1 Kg7 Bf2 Kh8 Be3 Kg7 
35   +0.65   00:07  31839K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Qe8 Bg3 Qe7 Bf2 
36   +0.65   00:08  44203K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Qd2 Qe8 Bg3 Qe7 Qe2 Kg8 Bf2 Kg7 
                            Be3 Rb8 Rd1 Qf7 Qd2 Qe7 Bf2 Rbc8 Be3 Rb8 
37   +0.65   00:09  61469K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Bg3 Kg8 Rd1 Kg7 Qd2 Qf7 Bf2 Qc7 
                            Bg3 Bd4 Rh1 Qe7 Bf2 Bc5 Rd1 Qc7 
38   +0.65   00:10  91411K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Bg3 Kg8 Rd1 Kg7 Qd2 Qf7 Bf2 Qc7 
                            Qc1 Qf7 Bg3 Qe7 
39   +0.65   00:13 132163K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Bg3 Kg8 Rd1 Kg7 Qd2 Qf7 Bf2 Qc7 
                            Qc1 Qf7 Qb2 Qe7 Qc1 Qf7 
40   +0.65   00:15 169739K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Bg3 Kg8 Rd1 Kg7 Qd2 Qf7 Bf2 Qc7 
                            Qc1 Qf7 Qb2 Qe7 Qc1 Qf7 
41   +0.65   00:20 248592K  Qc3 Qe7 Qd2 Rbc8 Bg1 Rb8 Bf2 Rbc8 Qc3 Rc7 Be3 Rb7 
                            Qc1 Rbb8 Bf2 Rbc8 Bg3 Kg8 Rd1 Kg7 Qd2 Qf7 Bf2 Qc7 
                            Qc1 Qf7 Qb2 Qe7 Qe2 Qf7 Be3 Qe7 Rh1 Kh8 Qd3 Kg7 Bd2 
                            Qf7 Be3 Qe7 
42   +0.65   01:20   1502M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Rf8 Rd1 Rfd8 Kg2 Rb8 Qc1 Qb4 
                            Qe3 Qa3 Qd3 Qc5 Qc3 Qa3 Rh1 Qc5 Qd2 Qa3 Qd3 Qc5 Rd1 
                            Rbc8 Qc2 Qe3 Rd5 Rb8 Qd1 Rbc8 Rd2 Qc5 Rd3 Qa3 Rd5 
                            Rc6 Rb5 Qb2+ Kg3 Qc3 Kh3 Rb8 Qd5 
43   +0.65   01:24   1586M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Rf8 Rd1 Rfd8 Kg2 Rb8 Qc1 Qb4 
                            Qe3 Qa3 Qd3 Qc5 Qc3 Qa3 Rh1 Qc5 Qd2 Qa3 Qd3 Qc5 Rd1 
                            Rbc8 Qc2 Qe3 Rd5 Rb8 Qd1 Rbc8 Rd2 Qc5 Rd3 Qa3 Rd5 
                            Rc6 Rb5 Qb2+ Kg3 Qc3 Kh3 Rb8 Qd5 
44   +0.65   01:29   1668M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Rf8 Rd1 Rfd8 Kg2 Rb8 Qc1 Qb4 
                            Qe3 Qa3 Qd3 Qc5 Qc3 Qa3 Rh1 Qc5 Qd2 Qa3 Qd3 Qc5 Rd1 
                            Rbc8 Qc2 Qe3 Rd5 Rb8 Qd1 Rbc8 Rd2 Qc5 Rd3 Qa3 Rd5 
                            Rc6 Rb5 Qb2+ Kg3 Qc3 Kh3 Rb8 Qd5 
45   +0.65   01:37   1806M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Rf8 Rd1 Rfd8 Kg2 Rb8 Qc1 Qb4 
                            Qe3 Qa3 Qd3 Qc5 Qc3 Qa3 Rh1 Qc5 Qd2 Qa3 Qd3 Qc5 Rd1 
                            Rbc8 Qc2 Qe3 Rd5 Rb8 Qd1 Rbc8 Rd2 Qc5 Rd3 Qa3 Rd5 
                            Rc6 Rb5 Qb2+ Kg3 Qc3 Kh3 Rb8 Qd5 
46   +0.65   01:46   1971M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Rf8 Rd1 Rfd8 Kg2 Rb8 Qc1 Qb4 
                            Qe3 Qa3 Qd3 Qc5 Qc3 Qa3 Rh1 Qc5 Qd2 Qa3 Qd3 Qc5 Rd1 
                            Rbc8 Qc2 Qe3 Rd5 Rb8 Qd1 Rbc8 Rd2 Qc5 Rd3 Qa3 Rd5 
                            Rc6 Rb5 Qb2+ Kg3 Qc3 Kh3 Rb8 Qd5 
47   +0.65   02:04   2356M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Rf8 Rd1 Rfd8 Kg2 Rb8 Qc1 Qb4 
                            Qe3 Qa3 Qd3 Qc5 Qc3 Qa3 Rh1 Qc5 Qd2 Qa3 Qd3 Qc5 Rd1 
                            Rbc8 Qc2 Qe3 Rd5 Rb8 Qd1 Rbc8 Rd2 Qc5 Rd3 Qa3 Rd5 
                            Rc6 Rb5 Qb2+ Kg3 Qc3 Kh3 Rb8 Qd5 
48   +0.65   02:35   2964M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Qd4 Qxd4 exd4 Rd5 
49   +0.65   03:04   3528M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Qd4 Qxd4 exd4 Kg2 d3 Rd1 Re8 
                            Rxd3 Rcd8 Rdd5 
50   +0.65   03:39   4210M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Qd2 Qc5 Qd1 Qa3 Re1 Rb8 Re2 Qc5 Rd2 Rbc8 
                            Rd3 Qa3 Rd5 Qb2+ Kg3 Qa3 Rb5 Rb8 Qg1 
Nodes: 4210875697
Nodes/second: 19192162
Best move: Qc3
Ponder move: Qe7

[Guenther]

The basic problem still exists though, as SF stubbornly maintains a score of +0.65 in all of your depths. This means it might still *find* the only losing move Bxc5 near the 100 ply draw rule, because it wants to avoid the draw?
The real score should be actually -0.01(dead draw but only Black can win).

Guenther

[d]1r1r4/3q2k1/1p1p1p1p/p1bRpRpP/P1P1P1P1/1P2BP2/2Q3K1/8 w - - 0 91
The game is still drawn because of the blocked position, but here SF plays 91.Bc5, exchanging the bishops, after which white is lost.

The latest SF never considers playing Bxc5, even at low depths:

Code: Select all

Searching: 1r1r4/3q2k1/1p1p1p1p/p1bRpRpP/P1P1P1P1/1P2BP2/2Q3K1/8 w - - 0 91
infinite: 0 ponder: 0 time: 0 increment: 0 moves to go: 0

 ...
48   +0.65   02:35   2964M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Qd4 Qxd4 exd4 Rd5 
49   +0.65   03:04   3528M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Kg3 Qc5 Qd2 Qd4 Qxd4 exd4 Kg2 d3 Rd1 Re8 
                            Rxd3 Rcd8 Rdd5 
50   +0.65   03:39   4210M  Qc3 Qe7 Qd2 Rbc8 Qd3 Kg8 Kg3 Rb8 Qd2 Rbc8 Qe2 Kg7 
                            Kg2 Rc7 Qf2 Rcc8 Rd1 Qc7 Rh1 Qf7 Qd2 Qe7 Qc1 Bxe3 
                            Qxe3 Qc7 Qd2 Qc5 Qd1 Qa3 Re1 Rb8 Re2 Qc5 Rd2 Rbc8 
                            Rd3 Qa3 Rd5 Qb2+ Kg3 Qa3 Rb5 Rb8 Qg1 
Nodes: 4210875697
Nodes/second: 19192162
Best move: Qc3
Ponder move: Qe7

[Henk]

Lately I removed all blocks, weak pawn, backward pawn or isolated pawn terms from my eval and what happened play improved. Might have to do with speed, speed and speed. Or maybe they were not sophisticated enough. Don't think it was bugs, bugs and bugs this time.