Author: Dagh Nielsen
Date: 14:05:30 01/09/06
Go up one level in this thread
Hi, thanks for a great post. I have some comments for two of the positions:
[D]8/5p2/6k1/pp6/3P3p/7K/PP4P1/8 b - - 0 40
>40...Kh5?? Even a weak player here can figure out that trying to protect the h
>pawn with a d runner is futile. Black's best chance (if he has one) is to play
>Kf5 and somehow hope that after snatching the d pawn he can hold the fort by
>trying to get his King to get the opposition. 1.37/1911 41.d5 0.76/20 7 41...Kg5
>1.02/20 14 42.d6 0.84/20 15 42...Kf6 0.90/19 9 43.Kxh4 1.64/20 13 43...Ke6
>1.90/19 7 44.Kg5 1.67/20 13 44...Kxd6 (b4) 2.25/20 10 45.Kf6 2.30/20 7 45...Kd5
>2.31/19 7 46.Kxf7 2.65/20 10 46...Ke5 2.54/18 6 47.Ke7 2.30/16 7 47...b4 2.80/19
>6 48.b3 3.64/21 7 48...Kd4 (Kf4) 11.09/22 51 49.Kf6 (Kd6) 7.57/17 6 49...Kc3
>9.22/16 9 50.g4 7.85/20 11 50...Kb2 9.28/16 11 51.g5 8.01/16 5 1–0
I agree that all the red flags should have been up before entering this ending,
but I am no so sure 40...Kh5 is such an unreasonable move. To me, it seems like
everything loses both the g and h pawn for the d pawn, so, for the engine, it is
only a question of delaying and pushing the rapidly deteriorating position as
far away in the horizon as possible. My analysis is simply Kf5 (instead of Kh5)
Kxh4 Ke5 (or f6 Kh5) Kg5 and black loses the g-pawn right away. I guess, in
losing positions engines will do all kinds of counter-intuitive stuff!?
[D]2r3k1/1R2K1p1/6B1/7P/8/8/8/8 w - - 0 113
>Here white has a completely winning position. He is a bishop up and he still has
>a pawn that can Queen. The easiest ways to win this position is to ofcourse
>flush out the King and try to keep him away from h8. Then you use strength of
>the extra bishop to take the black pawn. The rest is just moving your King in
>front and Queening the pawn. Here is an example of how to win this ending.
>5.88/13 3 [65.Bf7 Rd6 66.Kc5 Rf6 67.Bg6 Rf1 68.Ra8+ Ke7 69.Re8+ Kd7 70.Rg8 Ke6
>71.Rxg7 Rh1 72.Rf7 Rh4 73.Rf1 Ke5 74.Bf7 Rh3 75.Kc6 Rd3 76.Kc7 Ra3 77.Kd8 Rh3
>78.Ke7 Ke4 79.Kf6 Ke3 80.Kg7 Rg3+ 81.Bg6 Rh3 82.h6 Rh2 83.h7 Ke2 84.Rf8+-]
I will not deny that the position may be winning, but I don't think it is so
easy for engines to figure out the right plan :-)
OK, flushing out the King from h8, that means Bf7 or Kh7. Let's take your Bf7.
One winning plan is to move white king to h7. But what happens if black simply
keeps his rook on the 8th rank, and when white puts king on g6, black checks and
move back to the 8th?
OK, I figure your simpler plan is then Bf7-a2 and Rf7+ and Rxg7. But still,
there are lots of checks than can "push" such variants out beyond the horizon.
I don't know, figuring out the two above ideas, I see that your variation maybe
is the "logical" winning solution, it's just that maybe there are sidelines that
are very difficult to calculate so that the initial position can't be solved so
easily by search alone. And I don't think it is THAT easy to add knowledge to
the engine so that it will choose Bf7 as needed move; I faintly recall the
Topalov-Morozevich game from San Luis, just before the time control Topalov had
a very big advantage and had to choose between essentially two different winning
tries, but he opted for a "safe" one that gave Black a fortress somewhat similar
to this example, so that there were no longer no immediate threats to keep the
pressure, and Morozevich ended up drawing by a miracle perpetual. We sat there
on Playchess observing the game armed with our engines and said "oh-oh, did
Topalov just allow a fortress instead of this easy win"... I mean, Topalov
entered the fortress to avoid some practically risky line, and this seems quite
similar to Rybka allowing Kg8 because it cannot figure out the pawn win by
search!?
>113.h6? Rybka is forced to do a pawn move to stop the 50 move draw rule. It
>obviously has no clue how to win the won ending. Once the pawn is gone this is a
>draw.
If the engines have lost track, it is in my experience very unlikely they will
somehow be forced to find the right track once the 50 move draw looms... :-)
I firmly agree that Rybka has some endgame issues, but let me include two of my
earliest blitz games from playchess with Rybka where she impressed me a lot in
the ending, vs. Deep Shredder 9 and Deep Fritz 8. They both had far superior
hardware. The interesting part is that the evaluations differed a lot at the
last crucial moments; Rybka saw the eventual "truth" far earlier :-)
[Event "Rated game, 3m + 0s"]
[Site "Machines A"]
[Date "2005.12.05"]
[Round "?"]
[White "Nátas, Deep Shredder 9"]
[Black "Flying Saucers, Rybka 1.0 Beta 32-b"]
[Result "0-1"]
[ECO "C45"]
[WhiteElo "2601"]
[BlackElo "2661"]
[PlyCount "182"]
[EventDate "2005.12.05"]
[TimeControl "180"]
1. e4 {0} e5 {0} 2. Nf3 {0} Nc6 {0} 3. d4 {0} exd4 {0} 4. Nxd4 {0} Qh4 {0} 5.
Nc3 {0} Bb4 {0} 6. Be2 {0} Qxe4 {0} 7. Ndb5 {0} Bxc3+ {0} 8. bxc3 {0} Kd8 {0}
9. O-O {0} Nf6 {0} 10. Be3 {0} Re8 {0} 11. Bf3 {0.62/12 6} Qc4 {0.04/10 5} 12.
Rb1 {0.54/13 0} Ne5 {0.07/9 4} 13. Bd4 {0.99/12 7} d6 {0.18/10 10} 14. Be2 {
0.53/13 30} Qxa2 {0.03/8 1} 15. Ra1 {0.64/13 6} Qe6 {0.38/10 0} 16. Nxa7 {
0.70/13 5} Rb8 {0.28/10 0} 17. Nxc8 {0.77/12 4} Kxc8 {0.39/10 4} 18. c4 {
0.94/12 6} c5 {0.00/10 3} 19. Bb2 {0.92/12 4} Kc7 {-0.36/10 3} 20. Re1 {
0.75/12 0} Nxc4 {-0.56/9 1} 21. Bc3 {0.94/11 4} Ne4 {-0.34/11 0} 22. Qd3 {
0.24/11 6} f5 {-0.47/10 8} 23. Bxg7 {0.63/11 4} d5 {-0.23/9 1} 24. Qh3 {
1.31/11 7} Qg6 {-0.21/11 0} 25. Bh6 {1.35/10 1} Ned6 {0.27/8 2} 26. Bxc4 {
1.22/12 3} dxc4 {0.33/10 0} 27. Bf4 {1.24/12 8} Ra8 {0.37/10 3} 28. Rad1 {
1.11/12 9} Rxe1+ {0.52/11 10} 29. Rxe1 {1.36/17 0} Kc6 {0.32/11 2} 30. Bxd6 {
2.12/11 1} Kxd6 {0.59/11 3} 31. Qe3 {1.87/12 1} Qf6 {0.13/10 2} 32. c3 {
1.75/12 0} Ra3 {0.44/9 3} 33. Qf4+ {1.52/11 1} Kd7 {0.12/10 4} 34. Rd1+ {
1.86/12 9} Kc6 {0.22/11 3} 35. Qxc4 {2.16/13 0} b5 {0.71/10 8} 36. Qg8 {
2.05/14 0} Qe5 {0.59/9 4} 37. Qxh7 {1.88/11 0} Rxc3 {0.28/8 1} 38. Qd7+ {
1.41/10 2} Kb6 {0.01/0 0} 39. Qd8+ {1.41/10 1} Kc6 {0.53/10 3} 40. Qa8+ {
1.66/10 1} Kb6 {0.27/9 1} 41. h4 {1.38/10 0} b4 {0.30/9 1} 42. Qd8+ {1.93/9 1}
Qc7 {0.33/10 1} 43. Qf6+ {1.91/10 1} Kb5 {0.49/11 1} 44. Qxf5 {1.81/12 0} b3 {
0.43/10 1} 45. h5 {2.19/10 3} b2 {0.33/10 0} 46. Qb1 {2.00/11 1} Rb3 {0.81/11 3
} 47. h6 {2.25/12 0} Qc8 {1.21/11 20} 48. h7 {2.82/10 1} Qh8 {1.33/9 2} 49. Qg6
{2.82/10 2} Ra3 {0.86/8 1} 50. Qg8 {2.82/11 0} Ra8 {0.94/10 1} 51. Qb3+ {
2.82/12 0} Kc6 {0.94/10 0} 52. Qf3+ {1.82/10 5} Kb5 {0.52/11 0} 53. Qb3+ {
2.57/9 0} Kc6 {0.00/16 1} 54. Qd5+ {1.81/10 0} Kb6 {0.44/10 4} 55. Qe6+ {
1.81/12 0} Kb5 {0.46/8 0} 56. Qd7+ {1.81/11 0} Kc4 {0.34/9 3} 57. Qe6+ {
1.56/8 1} Kb5 {0.00/14 1} 58. Qd7+ {1.56/11 0} Kc4 {0.00/14 0} 59. Qg4+ {
1.09/9 1} Kb5 {0.47/9 2} 60. Qe2+ {1.09/11 0} c4 {0.05/10 4} 61. Rd5+ {
1.55/10 1} Kb4 {0.21/10 0} 62. Qe7+ {1.80/11 0} Kb3 {0.08/10 4} 63. Rb5+ {
1.91/10 1} Ka2 {0.00/10 0} 64. Qe4 {0.54/10 3} c3 {0.00/11 0} 65. g3 {0.66/10 1
} Ra7 {0.00/10 1} 66. Qd5+ {0.15/11 3} Kb1 {0.00/13 0} 67. Qd1+ {0.08/11 1} Ka2
{0.00/14 0} 68. Qb3+ {0.08/10 0} Kb1 {0.00/13 1} 69. Rb6 {0.20/9 1} Rd7 {
-0.97/9 1} 70. Rc6 {0.07/8 1} Qxh7 {-1.03/11 0} 71. Rxc3 {0.10/11 1} Qf5 {
-1.17/11 0} 72. Re3 {0.55/7 2} Rc7 {-0.74/11 0} 73. Kg2 {0.55/7 0} Qc8 {
-0.79/10 2} 74. Qd3+ {0.36/7 2} Rc2 {-0.88/11 0} 75. Re1+ {0.09/7 1} Ka2 {
-0.97/10 0} 76. Qd5+ {0.08/8 0} Qc4 {-0.94/10 1} 77. Qa8+ {0.04/8 1} Kb3 {
-1.16/10 2} 78. Qb7+ {0.02/9 0} Qb4 {-1.21/10 2} 79. Qf3+ {0.03/9 1} Rc3 {
-1.39/7 1} 80. Qd5+ {-0.64/8 5} Qc4 {-2.66/10 0} 81. Qb7+ {-0.89/8 2} Ka2 {
-3.71/10 0} 82. f4 {-1.27/7 1} Rc1 {-3.77/8 1} 83. Qa7+ {-3.91/7 4} Kb1 {
-3.53/11 0} 84. Qa5 {-3.91/8 0} Rxe1 {-8.32/7 1} 85. Qxe1+ {-1.43/5 0} Kc2 {
-8.32/10 0} 86. Qf2+ {-2.09/6 1} Kc3 {-8.38/11 0} 87. Qe1+ {-2.09/5 0} Kb3 {
-8.38/11 1} 88. Kh3 {-2.16/6 1} Qc8+ {-8.38/12 0} 89. Kh4 {-7.68/8 0} Qh8+ {
-8.38/12 1} 90. Kg4 {-8.46/9 0} Qg7+ {-8.38/12 1} 91. Kf5 {-8.46/9 0} Qh7+ {
Nátas,Deep Shredder 9 rinde -9.23/11 3} 0-1
[Event "Rated game, 3m + 0s"]
[Site "Machines A"]
[Date "2005.12.05"]
[Round "?"]
[White "Flying Saucers, Rybka 1.0 Beta 32-b"]
[Black "Firstjuni, Deep Fritz 8"]
[Result "1-0"]
[ECO "E03"]
[WhiteElo "2641"]
[BlackElo "2705"]
[PlyCount "91"]
[EventDate "2005.12.05"]
[TimeControl "180"]
1. d4 {0} Nf6 {0} 2. c4 {0} e6 {0} 3. g3 {0} d5 {0} 4. Bg2 {0} dxc4 {0} 5. Qa4+
{0} Nbd7 {0} 6. Qxc4 {0} c5 {0} 7. Nf3 {0} a6 {0} 8. O-O {0} b5 {0} 9. Qd3 {0}
Bb7 {-0.07/11 11} 10. Be3 {0.10/11 0} Be7 {-0.14/10 4} 11. Nc3 {0.19/9 4} O-O {
-0.30/10 4} 12. b3 {0.01/9 7} b4 {-0.56/10 5} 13. Na4 {0.00/12 0} Rc8 {
-0.58/10 6} 14. Rac1 {0.08/9 5} Qa5 {-0.46/10 4} 15. Nd2 {0.15/10 3} Bxg2 {
-0.63/11 1} 16. Kxg2 {0.14/10 3} Rfd8 {-0.76/10 0} 17. Rfd1 {0.13/10 3} cxd4 {
-0.46/10 4} 18. Rxc8 {0.11/10 1} Qd5+ {-0.49/11 0} 19. Nf3 {0.00/12 4} Rxc8 {
-0.44/12 0} 20. Bxd4 {0.00/11 3} Rd8 {-0.40/11 2} 21. Qc2 {0.45/10 5} Ne5 {
-0.50/10 3} 22. Qc7 {0.19/11 4} Nxf3 {-0.51/12 7} 23. exf3 {0.20/14 0} Qd6 {
-0.45/12 4} 24. Qxd6 {0.24/15 0} Rxd6 {-0.45/13 0} 25. Bxf6 {0.19/15 5} gxf6 {
-0.39/16 0} 26. Rxd6 {0.21/16 3} Bxd6 {-0.46/16 0} 27. Kf1 {0.31/15 4} f5 {
-0.47/15 3} 28. Ke2 {0.71/14 3} Kg7 {-0.20/13 2} 29. Kd3 {0.84/15 3} a5 {
0.43/14 5} 30. Kc4 {1.12/14 3} Bc7 {0.68/13 0} 31. Kb5 {1.26/14 1} f4 {
1.23/13 3} 32. Nc5 {1.47/14 4} h5 {1.75/13 0} 33. Nb7 {1.90/14 2} Be5 {
1.96/14 0} 34. Kxa5 {2.26/15 3} Bd4 {2.25/14 4} 35. Kxb4 {2.32/17 0} Bxf2 {
2.64/14 2} 36. gxf4 {2.43/16 0} Bg1 {2.97/14 2} 37. h3 {2.84/12 1} Kf6 {
3.36/14 2} 38. Nc5 {3.18/16 1} Be3 {3.87/14 2} 39. Nd3 {3.20/16 2} Ke7 {
4.02/15 3} 40. a4 {3.31/17 0} Kd6 {4.05/14 3} 41. a5 {3.44/16 2} Kc7 {4.33/15 0
} 42. Kb5 {3.64/16 2} Kb8 {4.83/15 0} 43. Ka6 {4.94/15 4} Bd4 {7.35/14 3} 44.
b4 {5.59/17 2} Bg7 {7.91/15 0} 45. b5 {8.72/16 17} h4 {14.61/16 0} 46. b6 {
Firstjuni,Deep Fritz 8 gibt auf (Lag: Av=0.43s, max=1.5s) 10.12/14 2} 1-0
This page took 0.01 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.