Author: Dieter Buerssner
Date: 10:07:14 02/02/05
[D] 4k3/5ppp/8/8/8/8/PPP5/3K4 w - -
This position is known to be a win for white, with 1. Ke2 and also with 1. Ke1.
Previous versions of Yace could "prove" it with the help of backwards analysis.
Current version can find it with a lot of patience from the front.
I let Yace think for a long time on it, and thought I could share my findings,
and also have a question at the end - so you might want to jump there. For the
first search, I forgot to enable logging. I pasted parts of the output into an
editor, but forgot the end. After 24 hours, score was +8.00 for 1. Ke2 (this
score is probably the score of a won kppkp position, that is detected by
"bitbases").
1959967574 35:16.3 0.41 18++ 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.a5 Kb7 5.b4 Ka6
6.c4 h4 7.Kg4 g5 8.c5 f5+ 9.Kh3 Kb5 10.Kh2 g4
11.Kg2 f4 12.Kg1 h3 13.Kh2 Ka6 14.c6 Ka7 15.b5
Kb8 16.b6 Ka8 17.c7 Kb7 18.a6+ Kxa6 {-80}
3641896757 1:04:57 1.14 18t 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4H 7.Kg4H g5H 8.Kh3H {HT} {0}
3690342980 1:05:50 1.14 18. 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 {HT} {0}
595514910 1:27:36 1.54 19++ 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.Kh2 g4 10.a5 Kb7
11.Kg2 f4 12.Kg1 h3 13.Kh2 f3 14.Kg3 h2 15.Kxh2
Kc7 16.a6 Kc6 17.b5+ Kd7 18.a7 Ke6 19.a8=Q {HT}
{1001}
2022351901 1:53:13 2.54 19++ 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.Kh2 g4 10.a5 Kb7
11.Kg2 f4 12.Kg1 h3 13.Kh2 f3 14.Kg3 Kc6 15.a6
Kd5 16.a7 h2 17.a8=Q+ Kc4 18.Kxg4 f2
2507637192 2:01:33 2.54 19t 1.Ke2 h5 2.Kf3 Kd7H 3.a4H Kc6H 4.c4H Kb7H 5.c5H
Kc6H 6.b4H h4H 7.Kg4H g5H 8.Kh3H {HT} {0}
2555159693 2:02:23 2.54 19. 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 {HT} {0}
2024319516 3:09:09 2.62 20t 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.a5 Kb5 10.Kh2 f4
11.Kg2 g4 12.Kg1 f3 13.Kf2 h3 14.Kg3 h2 15.Kxh2
f2 {HT} {80}
2316496574 3:14:17 2.62 20. 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.a5 Kb5 10.Kh2 f4
11.Kg2 g4 12.Kg1 f3 13.Kf2 h3 14.Kg3 h2 15.Kxh2
f2 {HT} {80}
2187771858 4:29:22 3.02 21++ 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.a5 Kb5 10.Kh2 f4
11.Kg2 g4 12.Kg1 f3 13.Kf2 h3 14.Kg3 h2 15.Kxh2
g3+ 16.Kxg3 Kc4 17.c6 Kd3 18.c7 Ke3 19.c8=Q f2
20.b5 Kd4
2308820459 5:49:42 4.02 21++ 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.a5 Kb5 10.Kh2 f4
11.Kg2 g4 12.Kg1 f3 13.Kf2 h3 14.Kg3 h2 15.Kxh2
Ka4 16.a6 Ka3 17.c6 f2 18.Kg2 Kb3 19.a7 f1=R
20.a8=Q g3 {581}
4251778459 6:23:31 4.02 21t 1.Ke2 h5 2.Kf3 Kd7H 3.a4H Kc6H 4.c4H Kb7H 5.c5H
Kc6H 6.b4H h4H 7.Kg4H g5H 8.Kh3H f5H 9.a5H Kb5H
10.Kh2H f4H 11.Kg2H h3+H 12.Kxh3H {HT} {80}
132859469 6:26:52 4.02 21. 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.a5 Kb5 10.Kh2 f4
11.Kg2 h3+ 12.Kxh3 {HT} {80}
4163453075 8:59:01 4.42 22++ 1.Ke2 h5 2.Kf3 Kd7 3.a4 Kc6 4.c4 Kb7 5.c5 Kc6
6.b4 h4 7.Kg4 g5 8.Kh3 f5 9.a5 Kb5 10.Kh2 f4
11.Kg2 h3+ 12.Kxh3 f3 13.Kh2 g4 14.Kg3 Kc4
15.a6 Kd3 16.a7 f2 17.a8=Q f1=R
Now a search for the second best move:
890455266 15:54.2 0.01 17. 1.a4 Kd7 2.a5 h5 3.Ke2 h4 4.Kf3 Kc6 5.b4 g5
6.a6 Kb6 7.b5 h3 8.c4 g4+ 9.Kxg4 h2 {HT} {80}
2061319523 36:48.4 0.00 18t 1.a4 h5 2.Ke1 f5 3.Kf2 h4 4.Kg2 f4 5.a5 Kd7
6.b4 Kc7 7.a6 Kb8 8.b5 Ka7 9.Kg1 Kb6 10.Kg2 Ka7
11.Kg1H Kb6H 12.Kg2H Ka7HR {0}
3315075472 59:23.2 0.01 18t+ 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 g4+ 5.Kxg4 f5+
6.Kxh4 Kd7 7.a4 f4 8.a5 Kc7 9.c4 f3 10.Kg3 Kb7
11.a6+ Kc6 12.a7 f2 13.a8=Q+ Kc5
3584365684 1:04:16 0.41 18++ 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 g4+ 5.Kxg4 f5+
6.Kxh4 Kd7 7.a4 f4 8.a5 Kc7 9.c4 f3 10.Kg3 Kb7
11.a6+ Kb6 12.a7 f2 13.a8=Q f1=Q
4035930039 1:12:25 1.41 18++ 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 g4+ 5.Kxg4 f5+
6.Kxh4 Kd7 7.a4 f4 8.a5 Kc7 9.c4 f3 10.Kg3 Kb7
11.a6+ Kb6 12.a7 f2 13.a8=Q f1=Q 14.Qd5 Qb1
15.Kf4 Qd3 {160}
494789691 1:26:06 2.64 18t 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 Kc4
15.c6 Kd3 16.c7 h2 17.Kxh2H f2H 18.c8=QH g3+H
19.Kg2H Ke2H 20.Kxg3H Kd2H {HT}
498683692 1:26:10 2.64 18. 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 Kc4
15.c6 Kd3 16.c7 h2 17.Kxh2 f2 18.c8=Q g3+
19.Kg2 Ke2 20.Kxg3 Kd2
1594267148 1:45:33 2.64 19t 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 {HT} {0}
1904697686 1:50:56 2.64 19. 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 {HT} {0}
4038543995 2:28:20 2.54 20t 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 f2
15.Kxf2 h2 16.Kg2 g3 17.Kh1 Kc6 18.a6 Kc7 19.b5
Kb8 20.b6H {HT} {80}
334770633 2:38:55 2.54 20. 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 f2
15.Kxf2 h2 16.Kg2 g3 17.Kh1 Kc6 18.a6 Kc7 19.b5
Kb8 20.b6 g2+H 21.Kxg2H Kc8H 22.b7+H {HT} {160}
2823564213 3:23:25 2.94 21++ 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 f2
15.Kxf2 Kc6 16.a6 Kc7 17.b5 h2 18.b6+ Kc6 19.a7
h1=R 20.a8=Q+ Kb5 {581}
1117492897 4:10:27 3.94 21++ 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 f2
15.Kxf2 Kxb4 16.a6 h2 17.Kg2 g3 18.c6 Kb3 19.a7
h1=R 20.a8=Q Rb1 {501}
620875846 5:18:31 4.08 21t 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 h2
15.Kxh2 f2 16.Kg2 {HT} {80}
1650063639 5:36:43 4.08 21. 1.Ke1 h5 2.Kf2 g5 3.Kg2 h4 4.Kh3 Kd8 5.a4 Kc7
6.a5 Kb7 7.c4 Ka6 8.b4 f5 9.c5 Kb5 10.Kh2 g4
11.Kg2 h3+ 12.Kg3 f4+ 13.Kh2 f3 14.Kg3 h2
15.Kxh2 f2 16.Kg2 f1=Q+H 17.Kxf1H g3H 18.Ke2H
Kc6H 19.Kf3H Kd7H 20.a6H {HT} {160}
And now for 3rd best move a really long think:
4010905683 2:30:47 0.00 21t 1.a4 h5 2.a5 Kd7 3.Ke2 h4 4.a6 Kc7 5.b4 g5 6.b5
Kb6 7.Kf2 g4 8.Kg2 Ka7 9.Kg1 h3 10.Kh2 Kb6
11.Kg3 Ka7 12.Kh2 {0}
1867644862 4:32:20 0.01 21t+ 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kd6
6.b6 Kc6 7.c5 Kb7 8.a4 Ka6 9.a5 Kb7 10.Kf4 h3
11.Kg3 h2 12.Kxh2H {HT} {80}
1787523651 5:53:28 0.40 21++ 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kd6
6.b6 Kc6 7.c5 Kb7 8.a4 Ka6 9.a5 Kb7 10.Kf4 h3
11.Kg3 h2 12.Kxh2 g6 13.Kh3 f4 14.Kg2 g5 15.Kh2
f3 16.Kh1 f2 17.a6+ Kc6 18.Kg2 g4 19.b7 f1=R
20.b8=Q Kxc5 {501}
1899252471 7:18:41 0.79 21t 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kd6
6.b6 Kc6 7.c5 Kb7 8.a4 Ka6 9.a5 Kb7 10.Kf4 g5+
11.Ke5 h3 12.Kd6 h2 13.c6+ Ka6 14.c7 h1=Q
15.c8=Q+ Kxa5 16.b7 Qh6+ 17.Ke5 Qh2+ 18.Kxf5
Qf4+ 19.Ke6 {HT} {0}
2856097488 7:36:45 0.79 21. 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kd6
6.b6 Kc6 7.c5 Kb7 8.a4 Ka6 9.a5 Kb7 10.Kf4 g5+
11.Ke5 h3 12.Kd6 h2 13.c6+ Ka6 14.c7 h1=Q
15.c8=Q+ Kxa5 16.b7 Qh6+ 17.Ke5 Qh2+ 18.Kxf5
Qf4+ 19.Ke6 {HT} {0}
2635219467 10:25:58 0.84 22t 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kd6
6.b6 Kc6 7.c5 Kb7 8.a4 g6 9.Kf2 f4 10.Kg2 Kc6
11.Kg1H g5H {HT} {0}
587689487 15:19:25 0.85 22t+ 1.a4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kc7
6.a5 Kb7 7.b6 Kc6 8.c3 h3 9.Kg3 h2 10.Kxh2 g5
11.Kh3 g4+ 12.Kg2 g3 {HT} {80}
1370117055 15:34:07 0.85 22t 1.a4 h5 2.Ke2 h4H 3.Kf3H f5H 4.b4H Kd7H 5.b5H
Kc7H 6.a5H Kb7H 7.b6H Kc6H 8.c3H {HT} {0}
3544303988 16:14:31 0.85 22. 1.a4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kc7
6.a5 Kb7 7.b6 Kc6 8.c3 {HT} {0}
659519855 22:12:28 0.85 23t 1.a4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kc7
6.a5 Kb7 7.b6 Kc6 8.c3 Kb7 9.c4 Kc6 10.c5 Kb7
11.Kf4 g6 12.Ke5 h3 13.Kd6 h2 14.c6+ Ka6 15.c7
h1=Q 16.c8=Q+ Kxa5 17.b7 Qh2+ 18.Ke6 Qa2+
19.Kf6 Qb2+ {HT} {-80}
2736953365 27:05:49 0.86 23t+ 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7 5.b5 Kd6
6.b6 Kc6 7.c5 Kb7 8.a4 g6 9.Kf2 f4 10.Kg2 Kc6
11.Kg1 g5 12.a5 h3 13.a6 {HT} {0}
929623794 34:58:24 0.88 23t 1.c4 h5 2.Ke2 h4 3.Kf3 f5 4.b4 Kd7H 5.b5H Kd6H
6.b6H Kc6H 7.c5H Kb7H 8.a4H f4H 9.Kxf4H h3H
{HT} {80}
As you can see, after a while (score was long at 0.0) some one pawn advantage is
found for 1.c4 and for 1.a4. Much of the line is hidden in the HT. The score
comes from a pawn up Q endgame. I think Odd Gunnar Malin mentioned, that
Averbach in one of his books discusses this position. He says, that 1. a4 wins,
too. Does anybody have access to the book? Are some lines given for 1. a4?
Regards,
Dieter
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