A position that engine(s) are clueless to understand

[Robert Flesher]

Hello folks, here is a position that engine(s) struggle to understand without TBs.

[d]K6Q/8/8/p7/8/8/6kp/8 w - - 0 0

[abulmo2]

I am not sure to understand, even my weak program dumb is able to draw it against stockfish 8.

[pgn][Event "Computer Chess Game"]
[Site "linux.home"]
[Date "2017.11.29"]
[Round "-"]
[White "dumb 1.0"]
[Black "Stockfish 8 64 POPCNT"]
[Result "1/2-1/2"]
[TimeControl "40/300"]
[FEN "K6Q/8/8/p7/8/8/6kp/8 w - - 0 1"]
[SetUp "1"]

{--------------
K . . . . . . Q
. . . . . . . .
. . . . . . . .
p . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . k p
. . . . . . . .
white to play
--------------}
1. Qb2+ {+9,78/17} Kg3 {-4,79/37 23} 2. Qe5+ {+10,44/20 4} Kh3
{-4,79/34 14} 3. Qf5+ {+10,43/18 7} Kg3 {-4,79/38 11} 4. Qf1 {+10,44/20 8}
a4 {-3,64/26 4} 5. Kb7 {+0,00/18 8} a3 {-2,31/28 5} 6. Kc6 {+10,43/17 8} a2
{-0,29/31 5} 7. Kd5 {+10,44/16 8} a1=Q {-0,13/34 0,1} 8. Qxa1 {+10,44/19 5}
Kg2 {+0,00/29 0,1} 9. Qa2+ {+10,44/20 6} Kg1 {+0,00/35 6} 10. Qb1+
{+10,44/22 4} Kg2 {+0,00/35 6} 11. Qe4+ {+9,98/24 8} Kg1 {+0,00/37 0,1} 12.
Qg4+ {+0,00/24 8} Kh1 {+0,00/39 7} 13. Qd4 {+9,97/25 8} Kg2 {+0,00/1 0,1}
14. Qe4+ {+10,37/20 6} Kg1 {+0,00/54 7} 15. Qb1+ {+0,00/23 8} Kg2
{+0,00/60 17} 16. Qc2+ {+9,78/24 8} Kg1 {+0,00/35 9} 17. Qd1+ {+9,97/24 8}
Kg2 {+0,00/52 6} 18. Qe2+ {+9,97/21 6} Kg1 {+0,00/28 6} 19. Qd1+
{+10,37/24 5} Kg2 {+0,00/80 45} 20. Qg4+ {+0,00/25 8} Kh1 {+0,00/51 35} 21.
Qd4 {+0,00/23 8} Kg2 {+0,00/1 0,1} 22. Qb2+ {+9,76/23 7} Kg1 {+0,00/35 6}
23. Qb6+ {+9,67/21 4} Kg2 {+0,00/34 7} 24. Qg6+ {+9,63/23 8} Kh1
{+0,00/37 0,1} 25. Qe6 {+9,62/21 6} Kg1 {+0,00/36 10} 26. Qe3+ {+9,67/21 9}
Kg2 {+0,00/27 6} 27. Qe2+ {+9,67/22 6} Kg1 {+0,00/42 24} 28. Qe3+
{+9,61/24 6} Kg2 {+0,00/56 8} 29. Qg5+ {+9,61/24 5} Kh1 {+0,00/34 3} 30.
Qe5 {+1,02/21 9} Kg1 {+0,00/31 10} 31. Qg3+ {+9,66/21 9} Kh1 {+0,00/34 8}
32. Qe5 {+9,61/23 5} Kg1 {+0,00/56 1,1} 33. Qg7+ {+9,61/23 10} Kh1
{+0,00/34 5} 34. Qc3 {+9,63/24 10} Kg2 {+0,00/31 2,3} 35. Qd2+
{+0,00/24 10} Kg1 {+0,00/36 0,1} 36. Qc1+ {+0,82/21 10} Kg2 {+0,00/48 0,6}
37. Qb2+ {+1,02/22 10} Kg1 {+0,00/38 0,1} 38. Qa1+ {+0,00/19 10} Kg2
{+0,00/49 1,7} 39. Qg7+ {+0,72/18 10} Kh1 {+0,00/39 0,1} 40. Qc3
{+0,71/19 10} Kg2 {+0,00/49 1,0} 41. Qc2+ {+0,00/19 7} Kg1 {+0,00/39 18}
42. Qg6+ {+0,72/18 6} Kh1 {+0,00/45 14} 43. Qf5 {+0,72/18 6} Kg1
{+0,00/36 18} 44. Qg5+ {+0,49/16 7} Kh1 {+0,00/46 31} 45. Qd8 {+0,70/19 6}
Kg1 {+0,00/37 39} 46. Qg8+ {+0,72/18 8} Kh1 {+0,00/39 0,1} 47. Qe6
{+0,61/18 8} Kg1 {+0,00/59 16} 48. Kc4 {+0,53/17 8} h1=Q {+0,00/29 8} 49.
Qe1+ {+0,00/16 8} Kg2 {+0,00/32 10} 50. Qe4+ {+0,00/17 8} Kg1
{+0,00/75 0,1} 51. Qd4+ {+0,00/16 8} Kf1 {+0,00/32 6} 52. Qf6+ {+0,37/16 8}
Kg2 {+0,00/32 7} 53. Qc6+ {+0,37/15 7} Kg1 {+0,00/29 13} 54. Qc5+
{+0,16/17 8} Kf1 {+0,00/24 5} 55. Qf5+ {+0,22/17 8} Ke2 {+0,00/28 1,4} 56.
Qe5+ {+0,17/16 6} Kf2 {+0,00/33 10} 57. Qd4+ {+0,19/16 4} Kg3
{+0,00/32 0,9} 58. Qe5+ {+0,14/16 8} Kf2 {+0,00/38 5} 59. Qc5+ {+0,08/15 6}
Ke1 {+0,00/30 7} 60. Qe3+ {+0,13/16 8} Kf1 {+0,00/33 0,1} 61. Qd3+
{+0,09/16 8} Kf2 {+0,00/30 5} 62. Qd2+ {+0,14/16 5} Kg3 {+0,00/36 21} 63.
Qg5+ {+0,00/18 8} Kf2 {+0,00/33 3} 64. Qc5+ {+0,24/16 8} Ke1 {+0,00/31 0,1}
65. Qe3+ {+0,12/15 8} Kf1 {+0,00/38 14} 66. Qd3+ {+0,12/17 8} Kg1
{+0,00/30 5} 67. Qd4+ {+0,20/15 8} Kf1 {+0,00/35 5} 68. Qf6+ {+0,11/16 5}
Kg2 {+0,00/34 14} 69. Qc6+ {+0,11/15 7} Kg1 {+0,00/37 8} 70. Qb6+
{+0,00/17 8} Kf1 {+0,00/36 0,1} 71. Qb1+ {+0,14/16 7} Kg2 {+0,00/79 0,1}
72. Qc2+ {+0,08/15 7} Kf1 {+0,00/27 1,2} 73. Qf5+ {+0,00/16 9} Ke2
{+0,00/28 1,2} 74. Qc2+ {+0,00/16 9} Kf1 {+0,00/27 1,6} 75. Qd1+
{+0,15/16 8} Kg2 {+0,00/73 1,0} 76. Qd5+ {+0,00/16 9} Kh2 {+0,00/29 1,1}
77. Qe5+ {+0,03/15 8} Kg1 {+0,00/39 0,1} 78. Qe1+ {+0,06/16 9} Kg2
{+0,00/127 0,1} 79. Qe4+ {+0,07/17 9} Kg1 {+0,00/127 0,1} 80. Qb1+
{+0,01/16 8} Kg2 {+0,00/34 5} 81. Qb7+ {+0,06/17 7} Kh2 {+0,00/36 16} 82.
Qh7+ {+0,00/17 6} Kg1 {+0,00/36 0,1} 83. Qd3 {+0,00/18 8} Qc6+
{+0,00/29 18} 84. Kd4 {+0,00/22 8} Qd6+ {+0,00/21 17} 85. Kc3
{+0,00/25 1,3} Qxd3+ {+0,00/20 21} 86. Kxd3 {+0,00/100 0,1}
{Xboard adjudication: Insufficient mating material} 1/2-1/2
[/pgn]

[Robert Flesher]

I am not sure to understand, even my weak program dumb is able to draw it against stockfish 8.

[pgn][Event "Computer Chess Game"]
[Site "linux.home"]
[Date "2017.11.29"]
[Round "-"]
[White "dumb 1.0"]
[Black "Stockfish 8 64 POPCNT"]
[Result "1/2-1/2"]
[TimeControl "40/300"]
[FEN "K6Q/8/8/p7/8/8/6kp/8 w - - 0 1"]
[SetUp "1"]

{--------------
K . . . . . . Q
. . . . . . . .
. . . . . . . .
p . . . . . . .
. . . . . . . .
. . . . . . . .
. . . . . . k p
. . . . . . . .
white to play
--------------}
1. Qb2+ {+9,78/17} Kg3 {-4,79/37 23} 2. Qe5+ {+10,44/20 4} Kh3
{-4,79/34 14} 3. Qf5+ {+10,43/18 7} Kg3 {-4,79/38 11} 4. Qf1 {+10,44/20 8}
a4 {-3,64/26 4} 5. Kb7 {+0,00/18 8} a3 {-2,31/28 5} 6. Kc6 {+10,43/17 8} a2
{-0,29/31 5} 7. Kd5 {+10,44/16 8} a1=Q {-0,13/34 0,1} 8. Qxa1 {+10,44/19 5}
Kg2 {+0,00/29 0,1} 9. Qa2+ {+10,44/20 6} Kg1 {+0,00/35 6} 10. Qb1+
{+10,44/22 4} Kg2 {+0,00/35 6} 11. Qe4+ {+9,98/24 8} Kg1 {+0,00/37 0,1} 12.
Qg4+ {+0,00/24 8} Kh1 {+0,00/39 7} 13. Qd4 {+9,97/25 8} Kg2 {+0,00/1 0,1}
14. Qe4+ {+10,37/20 6} Kg1 {+0,00/54 7} 15. Qb1+ {+0,00/23 8} Kg2
{+0,00/60 17} 16. Qc2+ {+9,78/24 8} Kg1 {+0,00/35 9} 17. Qd1+ {+9,97/24 8}
Kg2 {+0,00/52 6} 18. Qe2+ {+9,97/21 6} Kg1 {+0,00/28 6} 19. Qd1+
{+10,37/24 5} Kg2 {+0,00/80 45} 20. Qg4+ {+0,00/25 8} Kh1 {+0,00/51 35} 21.
Qd4 {+0,00/23 8} Kg2 {+0,00/1 0,1} 22. Qb2+ {+9,76/23 7} Kg1 {+0,00/35 6}
23. Qb6+ {+9,67/21 4} Kg2 {+0,00/34 7} 24. Qg6+ {+9,63/23 8} Kh1
{+0,00/37 0,1} 25. Qe6 {+9,62/21 6} Kg1 {+0,00/36 10} 26. Qe3+ {+9,67/21 9}
Kg2 {+0,00/27 6} 27. Qe2+ {+9,67/22 6} Kg1 {+0,00/42 24} 28. Qe3+
{+9,61/24 6} Kg2 {+0,00/56 8} 29. Qg5+ {+9,61/24 5} Kh1 {+0,00/34 3} 30.
Qe5 {+1,02/21 9} Kg1 {+0,00/31 10} 31. Qg3+ {+9,66/21 9} Kh1 {+0,00/34 8}
32. Qe5 {+9,61/23 5} Kg1 {+0,00/56 1,1} 33. Qg7+ {+9,61/23 10} Kh1
{+0,00/34 5} 34. Qc3 {+9,63/24 10} Kg2 {+0,00/31 2,3} 35. Qd2+
{+0,00/24 10} Kg1 {+0,00/36 0,1} 36. Qc1+ {+0,82/21 10} Kg2 {+0,00/48 0,6}
37. Qb2+ {+1,02/22 10} Kg1 {+0,00/38 0,1} 38. Qa1+ {+0,00/19 10} Kg2
{+0,00/49 1,7} 39. Qg7+ {+0,72/18 10} Kh1 {+0,00/39 0,1} 40. Qc3
{+0,71/19 10} Kg2 {+0,00/49 1,0} 41. Qc2+ {+0,00/19 7} Kg1 {+0,00/39 18}
42. Qg6+ {+0,72/18 6} Kh1 {+0,00/45 14} 43. Qf5 {+0,72/18 6} Kg1
{+0,00/36 18} 44. Qg5+ {+0,49/16 7} Kh1 {+0,00/46 31} 45. Qd8 {+0,70/19 6}
Kg1 {+0,00/37 39} 46. Qg8+ {+0,72/18 8} Kh1 {+0,00/39 0,1} 47. Qe6
{+0,61/18 8} Kg1 {+0,00/59 16} 48. Kc4 {+0,53/17 8} h1=Q {+0,00/29 8} 49.
Qe1+ {+0,00/16 8} Kg2 {+0,00/32 10} 50. Qe4+ {+0,00/17 8} Kg1
{+0,00/75 0,1} 51. Qd4+ {+0,00/16 8} Kf1 {+0,00/32 6} 52. Qf6+ {+0,37/16 8}
Kg2 {+0,00/32 7} 53. Qc6+ {+0,37/15 7} Kg1 {+0,00/29 13} 54. Qc5+
{+0,16/17 8} Kf1 {+0,00/24 5} 55. Qf5+ {+0,22/17 8} Ke2 {+0,00/28 1,4} 56.
Qe5+ {+0,17/16 6} Kf2 {+0,00/33 10} 57. Qd4+ {+0,19/16 4} Kg3
{+0,00/32 0,9} 58. Qe5+ {+0,14/16 8} Kf2 {+0,00/38 5} 59. Qc5+ {+0,08/15 6}
Ke1 {+0,00/30 7} 60. Qe3+ {+0,13/16 8} Kf1 {+0,00/33 0,1} 61. Qd3+
{+0,09/16 8} Kf2 {+0,00/30 5} 62. Qd2+ {+0,14/16 5} Kg3 {+0,00/36 21} 63.
Qg5+ {+0,00/18 8} Kf2 {+0,00/33 3} 64. Qc5+ {+0,24/16 8} Ke1 {+0,00/31 0,1}
65. Qe3+ {+0,12/15 8} Kf1 {+0,00/38 14} 66. Qd3+ {+0,12/17 8} Kg1
{+0,00/30 5} 67. Qd4+ {+0,20/15 8} Kf1 {+0,00/35 5} 68. Qf6+ {+0,11/16 5}
Kg2 {+0,00/34 14} 69. Qc6+ {+0,11/15 7} Kg1 {+0,00/37 8} 70. Qb6+
{+0,00/17 8} Kf1 {+0,00/36 0,1} 71. Qb1+ {+0,14/16 7} Kg2 {+0,00/79 0,1}
72. Qc2+ {+0,08/15 7} Kf1 {+0,00/27 1,2} 73. Qf5+ {+0,00/16 9} Ke2
{+0,00/28 1,2} 74. Qc2+ {+0,00/16 9} Kf1 {+0,00/27 1,6} 75. Qd1+
{+0,15/16 8} Kg2 {+0,00/73 1,0} 76. Qd5+ {+0,00/16 9} Kh2 {+0,00/29 1,1}
77. Qe5+ {+0,03/15 8} Kg1 {+0,00/39 0,1} 78. Qe1+ {+0,06/16 9} Kg2
{+0,00/127 0,1} 79. Qe4+ {+0,07/17 9} Kg1 {+0,00/127 0,1} 80. Qb1+
{+0,01/16 8} Kg2 {+0,00/34 5} 81. Qb7+ {+0,06/17 7} Kh2 {+0,00/36 16} 82.
Qh7+ {+0,00/17 6} Kg1 {+0,00/36 0,1} 83. Qd3 {+0,00/18 8} Qc6+
{+0,00/29 18} 84. Kd4 {+0,00/22 8} Qd6+ {+0,00/21 17} 85. Kc3
{+0,00/25 1,3} Qxd3+ {+0,00/20 21} 86. Kxd3 {+0,00/100 0,1}
{Xboard adjudication: Insufficient mating material} 1/2-1/2
[/pgn]

My point is that engine(s) think that white is winning. For example, Stockfish would trade to this endgame believing it is winning.

[Jouni]

Houdini 6 understands this:

1.Qg7+ Kf2 2.Qd4+ Kg3 3.Qe3+ Kg2 4.Qg5+ Kh3 5.Qd5 Kg3 6.Qe5+ Kg2 7.Qe4+ Kg3 8.Kb7 a4 9.Qe1+ Kg2 10.Qe2+ Kg3 11.Qd3+ Kg2 12.Qd2+ Kg3 13.Qc3+ Kg2 14.Qc6+ Kg3 15.Qg6+ Kf2 16.Qf5+ Kg3 17.Qe5+ Kg2 18.Qg7+ Kf1 19.Qh6 Kg2 20.Qg5+ Kh3 21.Qd5 Kg3 22.Kb6 a3 23.Qd3+ Kg2 24.Qd2+ Kg3 25.Qg5+ Kh3 26.Qf5+ Kg3 27.Qe5+ Kg2 28.Qe2+ Kg3 29.Qe3+ Kg2 30.Qe4+

+- (1.76) Depth: 28/95 00:00:04 29173kN

[Vinvin]

My point is that engine(s) think that white is winning. For example, Stockfish would trade to this endgame believing it is winning.

There's no more good reason to not use Syzygy : they weight 1 GB for 3-4-5 pieces, it's quite small for now.

[Robert Flesher]

Houdini 6 understands this:

1.Qg7+ Kf2 2.Qd4+ Kg3 3.Qe3+ Kg2 4.Qg5+ Kh3 5.Qd5 Kg3 6.Qe5+ Kg2 7.Qe4+ Kg3 8.Kb7 a4 9.Qe1+ Kg2 10.Qe2+ Kg3 11.Qd3+ Kg2 12.Qd2+ Kg3 13.Qc3+ Kg2 14.Qc6+ Kg3 15.Qg6+ Kf2 16.Qf5+ Kg3 17.Qe5+ Kg2 18.Qg7+ Kf1 19.Qh6 Kg2 20.Qg5+ Kh3 21.Qd5 Kg3 22.Kb6 a3 23.Qd3+ Kg2 24.Qd2+ Kg3 25.Qg5+ Kh3 26.Qf5+ Kg3 27.Qe5+ Kg2 28.Qe2+ Kg3 29.Qe3+ Kg2 30.Qe4+

+- (1.76) Depth: 28/95 00:00:04 29173kN

Scoring the position as 1.76? When it's a draw?

[Robert Flesher]

My point is that engine(s) think that white is winning. For example, Stockfish would trade to this endgame believing it is winning.

There's no more good reason to not use Syzygy : they weight 1 GB for 3-4-5 pieces, it's quite small for now.

This is true, but the position without TB was the point.

[MikeB]

Hello folks, here is a position that engine(s) struggle to understand without TBs.

[d]K6Q/8/8/p7/8/8/6kp/8 w - - 0 0

Thanks for sharing - but it’s nothing new under the sun. There are thousands if not millions of positions that fall into this category without tbs - that’s why we have tbs. When we get 16 men tbs, we will have perfect knowledge about chess but your statement above will still be true. It’s not going to change. 😊

[Nordlandia]

[d]8/3b4/p3p3/3pB3/2kP4/8/1K6/8 w - - 0 57

Why isn't this position recognized as dead draw by 3200+ engine?

[MikeB]

It's not being recognized as a win and that's about the best you're going to get. The code to make it say 0.00 is not required to get the draw.