houdini3 search and mate scores

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Uri Blass
Posts: 10798
Joined: Thu Mar 09, 2006 12:37 am
Location: Tel-Aviv Israel

houdini3 search and mate scores

Post by Uri Blass »

I gave it 1 cpu and 1024 mbytes hash
at depth 23 it found mate in 46
I could expect at bigger depths to see only shorter mates or the same score but houdini shows at depth 24 mate in 48 at depth 25 mate in 65 at depth 26 mate in 75 at depth 27 mate in 80 and at depth 28 mate in 85(note that mate in more than 50 moves means a draw by the 50 move rule so I think that houdini should get draw score for these long mates

only later it can see shorter mates.

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8/8/8/3k4/8/8/8/5BBK w - - 18 1

Houdini_3_x64:
4/9 00:00 340 0 +6.47 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5
5/9 00:00 556 0 +6.51 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Kg3-f3
6/11 00:00 999 0 +6.59 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Kg3-f3 Ke5-d5 Kf3-f4
7/11 00:00 2,034 2,034,000 +6.56 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-e5 Bf1-d3
7/11 00:00 2,665 2,665,000 +6.57 Bg1-f2 Kd5-e4 Kh1-g2 Ke4-f4 Bf1-d3 Kf4-e5 Kg2-f3
8/13 00:00 4,102 2,051,000 +6.69 Bg1-f2 Kd5-e4 Kh1-g2 Ke4-f4 Bf1-d3 Kf4-e5 Kg2-f3 Ke5-d5 Bd3-e4+ Kd5-e5
9/13 00:00 6,798 2,266,000 +6.69 Bg1-f2 Kd5-e4 Kh1-g2 Ke4-f4 Bf1-d3 Kf4-e5 Kg2-f3 Ke5-d5 Bd3-e4+ Kd5-e5
9/15 00:00 9,922 2,480,000 +6.75 Bf1-d3 Kd5-e5 Kh1-g2 Ke5-d5 Kg2-f3 Kd5-e5 Bd3-e4 Ke5-e6 Bg1-d4
10/17 00:00 13,425 2,237,000 +6.80 Bf1-d3 Kd5-e5 Kh1-g2 Ke5-d5 Kg2-f3 Kd5-e5 Bd3-e4 Ke5-e6 Bg1-d4 Ke6-d6 Kf3-f4
10/17 00:00 18,754 2,083,000 +6.82 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Kg3-g4 Ke5-e6 Bf1-c4+ Ke6-d6 Kg4-f4 Kd6-c6 Kf4-e5
11/17 00:00 30,807 2,053,000 +6.92 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-d7
12/17 00:00 43,962 1,998,000 +6.93 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-d7 Bd4-e3
13/19 00:00 73,065 2,029,000 +6.97 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-d7 Bd4-e3 Kd7-e7 Bg2-e4
14/21 00:00 129,082 1,926,000 +7.05 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-d7 Bd4-e3 Kd7-e7 Bg2-e4 Ke7-d7 Be4-d5
15/25 00:00 233,241 1,911,000 +7.17 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-d7 Bd4-c5 Kd7-c7 Bg2-d5 Kc7-d7 Bc5-d6 Kd7-d8
16/28 00:00 385,405 1,966,000 +7.19 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-f7 Bg2-d5+ Kf7-g6 Bd4-e3 Kg6-h5 Ke5-f5 Kh5-h4 Be3-f2+ Kh4-h5 Bd5-f3+ Kh5-h6 Bf2-d4
17/29 00:00 634,041 2,006,000 +7.22 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-f7 Bg2-d5+ Kf7-g6 Bd4-e3 Kg6-g7 Ke5-f5 Kg7-f8 Be3-c5+ Kf8-e8 Kf5-e5 Ke8-d8 Ke5-e6 Kd8-c7 Bc5-d4 Kc7-d8 Bd5-g2 Kd8-c8 Ke6-d6 Kc8-d8 Kd6-e6 Kd8-c8
18/32 00:00 981,761 2,053,000 +7.22 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-f7 Bg2-d5+ Kf7-g6 Bd4-e3 Kg6-g7 Ke5-f5 Kg7-f8 Be3-c5+ Kf8-e8 Kf5-e5 Ke8-d8 Ke5-e6 Kd8-c7 Bc5-d4 Kc7-d8 Bd5-g2 Kd8-c8 Ke6-d6 Kc8-d8 Kd6-e6 Kd8-c8
19/35 00:01 1,745,408 2,082,000 +7.27 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Bd4-c5+ Ke7-f6 Bg2-d5 Kf6-g6 Bc5-d4 Kg6-h6 Kf4-f5 Kh6-h5 Bd4-e3 Kh5-h4 Be3-f2+ Kh4-h3 Bd5-e4 Kh3-h2 Kf5-e5 Kh2-h3 Be4-f3 Kh3-h2
20/35 00:01 2,911,863 2,119,000 +7.33 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-d3 Ke5-e6 Kg3-f4 Ke6-d5 Kf4-f5 Kd5-d6 Bd3-e4 Kd6-d7 Bg1-c5 Kd7-c8 Kf5-e6 Kc8-c7 Bc5-d4 Kc7-d8 Bd4-b6+ Kd8-e8 Be4-c6+ Ke8-f8 Bb6-d4 Kf8-g8 Bc6-e4 Kg8-f8 Be4-f3 Kf8-e8 Bf3-e4 Ke8-d8 Bd4-b6+
21/35 00:02 4,553,779 2,144,000 +7.33 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-d3 Ke5-e6 Kg3-f4 Ke6-d7 Kf4-e5 Kd7-c7 Bd3-e4 Kc7-d7 Be4-d5 Kd7-c7 Ke5-e6 Kc7-d8 Bd5-e4 Kd8-e8 Bg1-d4 Ke8-d8 Bd4-b6+ Kd8-c8 Bb6-c5 Kc8-c7 Bc5-d4 Kc7-d8 Bd4-b6+
22/35 00:03 7,133,373 2,174,000 +7.33 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-d3 Ke5-e6 Kg3-f4 Ke6-d7 Kf4-e5 Kd7-c7 Bd3-e4 Kc7-d7 Be4-d5 Kd7-c7 Ke5-e6 Kc7-d8 Bd5-g2 Kd8-e8 Bg1-d4 Ke8-f8 Bg2-f3 Kf8-e8 Bf3-e4 Ke8-f8 Be4-f3 Kf8-e8
23/39+ 00:03 8,315,385 2,192,000 +7.63 Kh1-g2
23/39+ 00:03 8,344,304 2,193,000 +8.25 Kh1-g2
23/47+ 00:04 8,571,901 2,188,000 +15.04 Kh1-g2
23/47 00:04 10,615,273 2,263,000 +M46 Kh1-g2 Kd5-e6 Kg2-f3 Ke6-e5 Bf1-c4 Ke5-f5 Bg1-d4 Kf5-g5 Bc4-d3 Kg5-h4 Kf3-f4 Kh4-h5 Bd3-e2+ Kh5-g6 Be2-f3 Kg6-f7 Bf3-d5+ Kf7-g6 Bd5-e4+ Kg6-h6 Kf4-f5 Kh6-h7 Kf5-g4+ Kh7-g8 Kg4-f4 Kg8-f7 Be4-d5+ Kf7-g6
24/47- 00:05 11,656,911 2,296,000 +M48 Kh1-g2 Kd5-e6
24/47 00:05 12,578,648 2,328,000 +M48 Kh1-g2 Kd5-e6 Kg2-f3 Ke6-f5 Bf1-d3+ Kf5-e6 Kf3-f4 Ke6-f6 Bd3-c4 Kf6-e7 Kf4-e5 Ke7-f8 Bg1-d4 Kf8-g7 Ke5-f4+ Kg7-g6 Bc4-f1 Kg6-f7 Kf4-f5 Kf7-e7 Bf1-d3 Ke7-f7 Bd3-c4+ Kf7-f8 Kf5-e5 Kf8-g7
25/47- 00:05 13,528,768 2,348,000 +M50 Kh1-g2 Kd5-e6
25/47 00:07 17,460,279 2,425,000 +M65 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-d3 Ke5-d5 Kg3-f4 Kd5-c6 Kf4-f5 Kc6-d5 Bd3-e2 Kd5-c6 Be2-c4 Kc6-b7 Bc4-d3 Kb7-c6 Bd3-c4 Kc6-b7
26/47- 00:08 19,787,201 2,458,000 +M67 Kh1-g2 Kd5-e4
26/47 00:10 25,550,371 2,514,000 +M75 Kh1-g2 Kd5-e6 Kg2-f3 Ke6-e7 Kf3-f4 Ke7-e6 Bf1-g2 Ke6-f6 Bg1-d4+ Kf6-e6 Kf4-e4 Ke6-d7 Ke4-e5 Kd7-d8 Ke5-d6 Kd8-e8 Kd6-e6 Ke8-d8 Bg2-f1 Kd8-c7 Bf1-a6 Kc7-b8 Ba6-d3 Kb8-a8 Bd3-e4+ Ka8-b8 Be4-d5 Kb8-c7 Bd5-g2 Kc7-d8 Bg2-f1
27/47- 00:11 28,771,607 2,535,000 +M77 Kh1-g2 Kd5-e6
27/47 00:14 36,387,719 2,571,000 +M80 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Bf1-g2 Kf5-e5 Kg3-g4 Ke5-f6 Bg1-d4+ Kf6-e6 Kg4-f4 Ke6-d7 Kf4-f5 Kd7-c8 Kf5-e6 Kc8-b8 Bg2-e4 Kb8-c7 Bd4-g1 Kc7-d8 Bg1-b6+ Kd8-c8 Bb6-c5 Kc8-c7 Bc5-d4 Kc7-b8 Bd4-b6 Kb8-c8 Bb6-c5
28/47- 00:15 40,882,863 2,588,000 +M82 Kh1-g2 Kd5-e4
28/47 00:18 47,278,982 2,609,000 +M85 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Bf1-g2 Kf5-e6 Kg3-f4 Ke6-d7 Kf4-e5 Kd7-e7 Bg2-e4 Ke7-d7 Bg1-d4 Kd7-d8 Ke5-d6 Kd8-e8 Kd6-e6 Ke8-d8 Bd4-b6+ Kd8-c8 Be4-c6 Kc8-b8 Bc6-d5 Kb8-c8 Bd5-g2 Kc8-b8 Bb6-d4 Kb8-c7 Bd4-g1 Kc7-c8 Bg1-b6 Kc8-b8
29/47 00:20 52,931,360 2,625,000 +M23 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Bf1-g2 Kf5-e5 Kg3-g4 Ke5-f6 Bg1-d4+ Kf6-e6 Bg2-e4 Ke6-e7 Kg4-f5 Ke7-d6 Kf5-f6 Kd6-d7 Bd4-c5 Kd7-d8 Kf6-e5 Kd8-c7 Ke5-e6 Kc7-c8 Ke6-d6 Kc8-d8 Bc5-d4 Kd8-e8 Be4-d5 Ke8-f8 Kd6-e6 Kf8-e8 Bd4-b6 Ke8-f8 Ke6-f6 Kf8-e8
30/47- 00:23 61,159,951 2,640,000 +M25 Kh1-g2 Kd5-e4
30/47 00:24 64,627,068 2,648,000 +M25 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-e7 Kf4-e5 Ke7-f7 Bg2-d5+ Kf7-e7 Bd4-c5+ Ke7-d8 Ke5-d6 Kd8-e8 Bc5-d4 Ke8-f8 Kd6-e6 Kf8-e8 Bd5-c6+ Ke8-d8 Ke6-d6 Kd8-c8 Bc6-e4 Kc8-d8 Be4-g2 Kd8-e8 Bg2-d5 Ke8-f8
31/47 00:27 71,617,068 2,652,000 +M23 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Bf1-g2 Kf5-e5 Kg3-g4 Ke5-f6 Bg1-d4+ Kf6-e6 Bg2-e4 Ke6-e7 Kg4-f5 Ke7-d6 Kf5-f6 Kd6-d7 Bd4-c5 Kd7-c8 Kf6-e6 Kc8-c7 Bc5-d4 Kc7-c8 Ke6-d6 Kc8-d8 Be4-g2 Kd8-e8 Bg2-d5 Ke8-f8 Kd6-e6 Kf8-e8 Bd5-c6+ Ke8-d8 Ke6-d6 Kd8-c8
32/47- 00:37 100,205,627 2,671,000 +M25 Kh1-g2 Kd5-e4
32/47 00:40 108,771,228 2,670,000 +M24 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-e5 Bf1-g2 Ke5-f5 Bg1-d4 Kf5-e6 Kg3-f4 Ke6-d6 Kf4-f5 Kd6-e7 Bg2-e4 Ke7-d6 Be4-g2 Kd6-e7
33/47 00:46 123,395,298 2,657,000 +M21 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Bf1-g2 Kf5-e5 Kg3-g4 Ke5-f6 Kg4-f4 Kf6-e7 Kf4-f5 Ke7-d6 Bg1-d4 Kd6-e7 Bd4-c5+ Ke7-d7 Bg2-e4 Kd7-d8 Kf5-e6 Kd8-c7 Be4-d5 Kc7-b8 Bc5-b6 Kb8-c8 Bd5-g2 Kc8-b8 Bg2-e4 Kb8-c8 Ke6-d6 Kc8-b8 Kd6-c6 Kb8-c8 Be4-f5+ Kc8-b8
34/47 00:56 148,703,533 2,651,000 +M21 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Bf1-g2 Kf5-e5 Kg3-g4 Ke5-f6 Kg4-f4 Kf6-e7 Kf4-f5 Ke7-d6 Bg1-d4 Kd6-e7 Bd4-c5+ Ke7-d7 Bg2-e4 Kd7-d8 Kf5-e6 Kd8-c7 Be4-d5 Kc7-b8 Bc5-b6 Kb8-c8 Bd5-g2 Kc8-b8 Bg2-e4 Kb8-c8 Ke6-d6 Kc8-b8 Kd6-c6 Kb8-c8 Be4-f5+ Kc8-b8
35/47 01:08 181,413,060 2,656,000 +M18 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-f6 Kf3-f4 Kf6-e6 Bf1-c4+ Ke6-d6 Kf4-f5 Kd6-d7 Kf5-e5 Kd7-e7 Bg1-c5+ Ke7-d7 Bc4-b5+ Kd7-c7 Ke5-e6 Kc7-c8 Ke6-d6 Kc8-b7 Kd6-d7 Kb7-a8 Bb5-a6 Ka8-b8 Bc5-d4 Kb8-a8 Kd7-c6 Ka8-b8 Kc6-b6 Kb8-a8 Ba6-b7+ Ka8-b8 Bd4-e5+
36/47 01:17 205,385,919 2,653,000 +M18 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-f6 Kf3-f4 Kf6-e6 Bf1-c4+ Ke6-d6 Kf4-f5 Kd6-d7 Kf5-e5 Kd7-e7 Bg1-c5+ Ke7-d7 Bc4-b5+ Kd7-c7 Ke5-e6 Kc7-c8 Ke6-d6 Kc8-b7 Kd6-d7 Kb7-a8 Bb5-a6 Ka8-b8 Bc5-d4 Kb8-a8 Kd7-c6 Ka8-b8 Kc6-b6 Kb8-a8 Ba6-b7+ Ka8-b8 Bd4-e5+
37/47 01:31 240,394,480 2,645,000 +M18 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-f6 Kf3-f4 Kf6-e6 Bf1-c4+ Ke6-d6 Kf4-f5 Kd6-d7 Kf5-e5 Kd7-e7 Bg1-c5+ Ke7-d7 Bc4-b5+ Kd7-c7 Ke5-e6 Kc7-c8 Ke6-d6 Kc8-b7 Kd6-d7 Kb7-b8 Bb5-a6 Kb8-a8 Bc5-d4 Ka8-b8 Kd7-c6 Kb8-a8 Kc6-b6 Ka8-b8 Bd4-e5+ Kb8-a8 Ba6-b7+
38/47 01:49 287,925,092 2,638,000 +M18 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-f6 Kf3-f4 Kf6-e6 Bf1-c4+ Ke6-d6 Kf4-f5 Kd6-d7 Kf5-e5 Kd7-e7 Bg1-c5+ Ke7-d7 Bc4-b5+ Kd7-c7 Ke5-e6 Kc7-c8 Ke6-d6 Kc8-b7 Kd6-d7 Kb7-b8 Bb5-a6 Kb8-a8 Bc5-d4 Ka8-b8 Kd7-c6 Kb8-a8 Kc6-b6 Ka8-b8 Bd4-e5+ Kb8-a8 Ba6-b7+
39/47 02:22 375,698,922 2,635,000 +M17 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-e6 Kf3-e4 Ke6-d6 Bf1-c4 Kd6-c6 Ke4-e5 Kc6-d7 Bc4-b5+ Kd7-e7 Bg1-c5+ Ke7-f7 Ke5-f5 Kf7-g7 Bb5-e8 Kg7-h6 Be8-g6 Kh6-g7 Kf5-g5 Kg7-h8 Kg5-f6 Kh8-g8 Bg6-d3 Kg8-h8 Kf6-g6 Kh8-g8 Bd3-c4+ Kg8-h8 Bc5-d4+
40/47 02:49 444,657,564 2,629,000 +M17 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-e6 Kf3-e4 Ke6-d6 Bf1-c4 Kd6-c6 Ke4-e5 Kc6-d7 Bc4-b5+ Kd7-e7 Bg1-c5+ Ke7-f7 Ke5-f5 Kf7-g7 Bb5-e8 Kg7-h6 Be8-g6 Kh6-g7 Kf5-g5 Kg7-h8 Kg5-f6 Kh8-g8 Bg6-d3 Kg8-h8 Kf6-g6 Kh8-g8 Bd3-c4+ Kg8-h8 Bc5-d4+
41/47 03:26 541,095,950 2,622,000 +M17 Kh1-g2 Kd5-e4 Kg2-g3 Ke4-f5 Kg3-f3 Kf5-e6 Kf3-e4 Ke6-d6 Bf1-c4 Kd6-c6 Ke4-e5 Kc6-d7 Bc4-b5+ Kd7-e7 Bg1-c5+ Ke7-f7 Ke5-f5 Kf7-g7 Bb5-e8 Kg7-h6 Be8-g6 Kh6-g7 Kf5-g5 Kg7-h8 Kg5-f6 Kh8-g8 Bg6-d3 Kg8-h8 Kf6-g6 Kh8-g8 Bd3-c4+ Kg8-h8 Bc5-d4+
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syzygy
Posts: 5696
Joined: Tue Feb 28, 2012 11:56 pm

Re: houdini3 search and mate scores

Post by syzygy »

Uri Blass wrote:I gave it 1 cpu and 1024 mbytes hash
at depth 23 it found mate in 46
I could expect at bigger depths to see only shorter mates or the same score but houdini shows at depth 24 mate in 48 at depth 25 mate in 65 at depth 26 mate in 75 at depth 27 mate in 80 and at depth 28 mate in 85(note that mate in more than 50 moves means a draw by the 50 move rule so I think that houdini should get draw score for these long mates
It should not, because in this position the answer "draw" would be far more incorrect than the answer "mate (in 85)".

This is how transposition tables work. Efficient transposition tables will never work completely correctly with the 50-move rule. But in this case there is not even a problem. If you don't like to see "+M85", then just imagine it says "0.00" there.
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Uri Blass
Posts: 10798
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Location: Tel-Aviv Israel

Re: houdini3 search and mate scores

Post by Uri Blass »

syzygy wrote:
Uri Blass wrote:I gave it 1 cpu and 1024 mbytes hash
at depth 23 it found mate in 46
I could expect at bigger depths to see only shorter mates or the same score but houdini shows at depth 24 mate in 48 at depth 25 mate in 65 at depth 26 mate in 75 at depth 27 mate in 80 and at depth 28 mate in 85(note that mate in more than 50 moves means a draw by the 50 move rule so I think that houdini should get draw score for these long mates
It should not, because in this position the answer "draw" would be far more incorrect than the answer "mate (in 85)".

This is how transposition tables work. Efficient transposition tables will never work completely correctly with the 50-move rule. But in this case there is not even a problem. If you don't like to see "+M85", then just imagine it says "0.00" there.
I do not say that houdini should get draw score for the root position but only for long mates.

The fact that there is a long mate does not mean that there is no shorter mate and the score for the root position is not based only on the long mates but also on shorter lines.
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syzygy
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Joined: Tue Feb 28, 2012 11:56 pm

Re: houdini3 search and mate scores

Post by syzygy »

Uri Blass wrote:
syzygy wrote:
Uri Blass wrote:I gave it 1 cpu and 1024 mbytes hash
at depth 23 it found mate in 46
I could expect at bigger depths to see only shorter mates or the same score but houdini shows at depth 24 mate in 48 at depth 25 mate in 65 at depth 26 mate in 75 at depth 27 mate in 80 and at depth 28 mate in 85(note that mate in more than 50 moves means a draw by the 50 move rule so I think that houdini should get draw score for these long mates
It should not, because in this position the answer "draw" would be far more incorrect than the answer "mate (in 85)".

This is how transposition tables work. Efficient transposition tables will never work completely correctly with the 50-move rule. But in this case there is not even a problem. If you don't like to see "+M85", then just imagine it says "0.00" there.
I do not say that houdini should get draw score for the root position but only for long mates.
Yes, and to that I say: mate (in 85) is far more correct than "draw".

In general, finding a mate in 85 does not imply a 50-move rule draw. When an engine finds a mate score in the hash table, say mate in 40, it has no way of knowing whether the path to mate "fits" within the number of moves left. The path to mate will usually have captures or pawn moves.

In this particular case, it is clear that any path to mate will not have pawn moves (since there are no pawns) and will not have captures (since capturing a bishop leads to draw). So yes, an engine could have specialised knowledge for the case KBBvK that will let it evaluate a mate in 85 as a draw. This would be completely stupid, since KBBvK can easily be won within 50 moves.

If you don't want to see a mate in 85 here, then at least ask for a score of +50.00 or so. A draw score is just silly for KBBvK.
The fact that there is a long mate does not mean that there is no shorter mate and the score for the root position is not based only on the long mates but also on shorter lines.
Exactly, so a draw score does not make any sense here.

Maybe what you mean is that during the search, if probing the hash table results in mate in 40 and the 50-move counter is already at 10 moves / 20 ply, the search should evaluate the position as a draw. As I have tried to explain, that would be wrong for very many reasons.

The fact of the matter is that the 50-move rule inherently does not play nice with transposition tables. There is no way around this, unless you want to give up most of the benefit of hash tables.
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michiguel
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Re: houdini3 search and mate scores

Post by michiguel »

syzygy wrote:
Uri Blass wrote:
syzygy wrote:
Uri Blass wrote:I gave it 1 cpu and 1024 mbytes hash
at depth 23 it found mate in 46
I could expect at bigger depths to see only shorter mates or the same score but houdini shows at depth 24 mate in 48 at depth 25 mate in 65 at depth 26 mate in 75 at depth 27 mate in 80 and at depth 28 mate in 85(note that mate in more than 50 moves means a draw by the 50 move rule so I think that houdini should get draw score for these long mates
It should not, because in this position the answer "draw" would be far more incorrect than the answer "mate (in 85)".

This is how transposition tables work. Efficient transposition tables will never work completely correctly with the 50-move rule. But in this case there is not even a problem. If you don't like to see "+M85", then just imagine it says "0.00" there.
I do not say that houdini should get draw score for the root position but only for long mates.
Yes, and to that I say: mate (in 85) is far more correct than "draw".

In general, finding a mate in 85 does not imply a 50-move rule draw. When an engine finds a mate score in the hash table, say mate in 40, it has no way of knowing whether the path to mate "fits" within the number of moves left. The path to mate will usually have captures or pawn moves.

In this particular case, it is clear that any path to mate will not have pawn moves (since there are no pawns) and will not have captures (since capturing a bishop leads to draw). So yes, an engine could have specialised knowledge for the case KBBvK that will let it evaluate a mate in 85 as a draw. This would be completely stupid, since KBBvK can easily be won within 50 moves.

If you don't want to see a mate in 85 here, then at least ask for a score of +50.00 or so. A draw score is just silly for KBBvK.
The fact that there is a long mate does not mean that there is no shorter mate and the score for the root position is not based only on the long mates but also on shorter lines.
Exactly, so a draw score does not make any sense here.

Maybe what you mean is that during the search, if probing the hash table results in mate in 40 and the 50-move counter is already at 10 moves / 20 ply, the search should evaluate the position as a draw. As I have tried to explain, that would be wrong for very many reasons.

The fact of the matter is that the 50-move rule inherently does not play nice with transposition tables. There is no way around this, unless you want to give up most of the benefit of hash tables.
Mate scores are a very special case of "scores" compared to +9.00 etc. The score per se is just "check mate", meaning, my side wins and the chances to win are 100%. However, since progress is needed, it contains an extra little piece of information, which is how distant that win is. That implies that the true meaning of a mate score is not "Mate in 10", but "Mate in 10 or better". From this perspective, Mate in 85 is not a wrong score.

Traditionally, an engine always found shorter and shorter mates, and if it did not do that, some bug was present. With all the current pruning, not anymore. It is possible that a mate is detected, but later it is converted to a longer one (a defensive move was not pruned anymore). In Gaviota I worked a little bit about this but still these weird effects show up. The behavior is much better, but still there is a little hiccup going from mate in 24 to 25.

Code: Select all

        30   1:      0.0    +6.06  1.Kg2
       130   2:      0.0    +6.06  1.Kg2 Kd6
       553   3:      0.0    +6.07  1.Kg2 Kd6 2.Kf3
      2013   4:      0.0    +6.06  1.Kg2 Ke4 2.Bc4 Ke5
      4594   5:      0.1    +6.08  1.Kg2 Ke4 2.Bc4 Kf4 3.Kf2
     13096   6:      0.1    +6.07  1.Kg2 Ke4 2.Kg3 Ke5 3.Bg2 Kf5
     28929   7:      0.2    +6.08  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4
     37040   8       0.2    +6.08  1.Bd3 Ke5 2.Kg2 Kd6 3.Bh2+ Kd5 4.Kf3
                                   Kd4 5.Be4
     63707   8:      0.3    +6.08  1.Bd3 Ke5 2.Kg2 Kd6 3.Bh2+ Kd5 4.Kf3
                                   Kd4 5.Be4
     71833   9       0.3    +6.09  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Ke4
    121205   9:      0.4    +6.09  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Ke4
    135016  10       0.5    +6.09  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Bf1 Ke6
                                   5.Bc4+ Ke5 6.Ke3
    200198  10       0.6    +6.10  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bc4
    248660  10:      0.7    +6.10  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bc4
    297225  11       0.8    +6.10  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bd3 [>]
    426039  11:      1.0    +6.10  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bd3 [>]
    525286  12       1.2    +6.10  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bd3 [>]
    749916  12:      1.5    +6.10  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bd3 [>]
    925281  13       1.7    +6.11  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bd3 Ke6 7.Bc4+ Kf6 [<]
   1237653  13:      2.1    +6.11  1.Kg2 Ke5 2.Bh2+ Kd4 3.Kf3 Kd5 4.Ke3
                                   Ke6 5.Ke4 Kf6 6.Bd3 Ke6 7.Bc4+ Kf6 [<]
   1692629  14       2.6    +6.12  1.Kg2 Ke5 2.Kf3 Kd6 3.Ke4 Ke6 4.Bc4+
                                   Kd6 5.Kf5 Kd7 6.Ke5 Kc6 7.Ke6 Kc7 8.Bb5
   2186532  14:      3.1    +6.12  1.Kg2 Ke5 2.Kf3 Kd6 3.Ke4 Ke6 4.Bc4+
                                   Kd6 5.Kf5 Kd7 6.Ke5 Kc6 7.Ke6 Kc7 8.Bb5
   2955492  15       3.9    +6.13  1.Kg2 Ke5 2.Kf3 Kd6 3.Ke4 Ke6 4.Bc5 Kf6
                                   5.Bc4 Kg5 6.Be7+ Kg6 7.Ke5 Kg7 8.Kf5
                                   Kh6
   3707235  15:      4.7    +6.13  1.Kg2 Ke5 2.Kf3 Kd6 3.Ke4 Ke6 4.Bc5 Kf6
                                   5.Bc4 Kg5 6.Be7+ Kg6 7.Ke5 Kg7 8.Kf5
                                   Kh6
   4978931  16       5.9    +6.14  1.Kg2 Ke5 2.Kg3 Kd6 3.Bd3 Kd5 4.Kf4 Kd6
                                   5.Bc4 Kd7 6.Ke5 Kc6 7.Bf1 Kb7 8.Bd3 [>]
   5748469  16:      6.6    +6.14  1.Kg2 Ke5 2.Kg3 Kd6 3.Bd3 Kd5 4.Kf4 Kd6
                                   5.Bc4 Kd7 6.Ke5 Kc6 7.Bf1 Kb7 8.Bd3 [>]
   8160232  17       8.9    +6.14  1.Kg2 Ke5 2.Kg3 Kd6 3.Bd3 Kd5 4.Kf4 Kd6
                                   5.Bc4 Kd7 6.Ke5 Kc6 7.Bf1 Kb7 8.Bd3 Kc7
                                   [<]
  10455918  17:     11.1    +6.14  1.Kg2 Ke5 2.Kg3 Kd6 3.Bd3 Kd5 4.Kf4 Kd6
                                   5.Bc4 Kd7 6.Ke5 Kc6 7.Bf1 Kb7 8.Bd3 Kc7
                                   [<]
  12590188  18      13.1    +6.15  1.Kg2 Ke5 2.Kf3 Kd6 3.Bc4 Ke5 4.Bc5 Kf5
                                   5.Bd4 Kg5 6.Ke4 Kg6 7.Ke5 Kg5 8.Be3+
                                   Kg4 9.Be2+ Kg3 10.Ba7 [>]
  13942201  18:     14.3    +6.15  1.Kg2 Ke5 2.Kf3 Kd6 3.Bc4 Ke5 4.Bc5 Kf5
                                   5.Bd4 Kg5 6.Ke4 Kg6 7.Ke5 Kg5 8.Be3+
                                   Kg4 9.Be2+ Kg3 10.Ba7 [>]
  17439120  19      17.6    +6.16  1.Kg2 Ke5 2.Kf3 Kd6 3.Kf4 Ke6 4.Bc4+
                                   Kd6 5.Kf5 Kc6 6.Ke6 Kc7 7.Bb5 Kb7 8.Kd7
                                   Kb8 9.Ba6 Ka8 10.Kd8 Kb8
  19481764  19:     19.5    +6.16  1.Kg2 Ke5 2.Kf3 Kd6 3.Kf4 Ke6 4.Bc4+
                                   Kd6 5.Kf5 Kc6 6.Ke6 Kc7 7.Bb5 Kb7 8.Kd7
                                   Kb8 9.Ba6 Ka8 10.Kd8 Kb8
  23690793  20      23.4    +6.19  1.Kg2 Ke5 2.Kg3 Kf5 3.Bd3+ Ke5 4.Ba7
                                   Kd5 5.Kf4 Kd6 6.Be3 Kd5 7.Bg1 Kd6 8.Bc4
                                   Kc6 9.Be3 Kb7 10.Ke5 Kc7 [<]
  25155350  20:     24.8    +6.19  1.Kg2 Ke5 2.Kg3 Kf5 3.Bd3+ Ke5 4.Ba7
                                   Kd5 5.Kf4 Kd6 6.Be3 Kd5 7.Bg1 Kd6 8.Bc4
                                   Kc6 9.Be3 Kb7 10.Ke5 Kc7 [<]
  43508372  21      41.8    +6.19  1.Kg2 Ke5 2.Kg3 Kf5 3.Bd3+ Ke5 4.Ba7
                                   Kd5 5.Kf4 Kd6 6.Be3 Kd5 7.Kf5 Kd6 8.Bc4
                                   Ke7 9.Bc5+ Kd7 10.Bb5+ Kc7 11.Ke6 Kb7
                                   12.Bd4 [>]
  47294606  21      45.3      :-)  1.Bg2+
  52420172  21      50.1  +Mat_31  1.Bg2+ Kc4 2.Kh2 Kb5 3.Kg3 Kc4 4.Kf4
                                   Kc3 5.Be4 Kb4 6.Ke5 Kb3 7.Kd4 Ka4 8.Be3
                                   Ka3 9.Kd5 [>]
  54275576  21      51.9  +Mat_30  1.Kh2 Ke5 2.Kg3 Kf5 3.Bd3+ Ke5 4.Kf3
                                   Kd5 5.Kf4 Ke6 6.Be4 Kd6 7.Kf5 Ke7 8.Ke5
                                   Kd7 9.Bd4 Ke7 [<]
  55851576  21:     53.3  +Mat_30  1.Kh2 Ke5 2.Kg3 Kf5 3.Bd3+ Ke5 4.Kf3
                                   Kd5 5.Kf4 Ke6 6.Be4 Kd6 7.Kf5 Ke7 8.Ke5
                                   Kd7 9.Bd4 Ke7 [<]
  57187824  22      54.6  +Mat_25  1.Kh2 Ke5 2.Kg3 Kf5 3.Kf3 Ke5 4.Bc4 Kd6
                                   5.Ke4 Kc6 6.Ke5 Kd7 7.Bd3 Ke7 8.Bc5+
                                   Kd7 9.Bb5+ Kc7 10.Ke6 Kb7 [<]
  58842275  22:     56.1  +Mat_25  1.Kh2 Ke5 2.Kg3 Kf5 3.Kf3 Ke5 4.Bc4 Kd6
                                   5.Ke4 Kc6 6.Ke5 Kd7 7.Bd3 Ke7 8.Bc5+
                                   Kd7 9.Bb5+ Kc7 10.Ke6 Kb7 [<]
  60509241  23      57.7  +Mat_24  1.Kh2 Ke5 2.Kg3 Kf5 3.Bg2 Ke5 4.Kg4 Ke6
                                   5.Bc5 Kd7 6.Kf5 Kc7 7.Bf3 Kd7 8.Ke5 Kc7
                                   9.Ke6 Kb8 [<]
  62435237  23:     59.5  +Mat_24  1.Kh2 Ke5 2.Kg3 Kf5 3.Bg2 Ke5 4.Kg4 Ke6
                                   5.Bc5 Kd7 6.Kf5 Kc7 7.Bf3 Kd7 8.Ke5 Kc7
                                   9.Ke6 Kb8 [<]
  64670204  24      61.6  +Mat_25  1.Kh2 Ke5 2.Kg3 Kf5 3.Bg2 Ke5 4.Kg4 Ke6
                                   5.Bc5 Kf6 6.Kf4 Ke6 7.Bc6 Kf6 8.Bd7 Kg6
                                   9.Bb5 Kh6 10.Bd3 Kh5 [<]
  67549980  24      64.3  +Mat_24  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Bc4 Kc6 8.Ke6 Kc7
                                   9.Bd5 Kd8 10.Bb7 Kc7 [<]
  68083942  24:     64.8  +Mat_24  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Bc4 Kc6 8.Ke6 Kc7
                                   9.Bd5 Kd8 10.Bb7 Kc7 [<]
  69012443  25      65.7  +Mat_23  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Bb5+ Kc7 8.Ke6
                                   Kb7 9.Kd6 Kb8 10.Kc6 Kc8 11.Bd3 [>]
  72043417  25:     68.5  +Mat_23  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Bb5+ Kc7 8.Ke6
                                   Kb7 9.Kd6 Kb8 10.Kc6 Kc8 11.Bd3 [>]
  75724350  26      72.0  +Mat_22  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Be4 Kc7 8.Ke6 Kc8
                                   9.Be5 Kd8 10.Bd3 Kc8 11.Ba6+ Kd8 12.Bd6
                                   [>]
  80034591  26:     76.1  +Mat_22  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Be4 Kc7 8.Ke6 Kc8
                                   9.Be5 Kd8 10.Bd3 Kc8 11.Ba6+ Kd8 12.Bd6
                                   [>]
  81656748  27      77.6  +Mat_20  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Be4 Ke7 8.Bf5 Kf7
                                   9.Kd6 Ke8 10.Bg6+ Kd8 11.Bc5 Kc8 12.Kc6
                                   Kd8 [<]
  86692106  27:     82.4  +Mat_20  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bd4 Kc6 6.Ke5 Kd7 7.Be4 Ke7 8.Bf5 Kf7
                                   9.Kd6 Ke8 10.Bg6+ Kd8 11.Bc5 Kc8 12.Kc6
                                   Kd8 [<]
 100163079  28      95.1  +Mat_20  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bc4 Kc6 6.Ke5 Kd7 7.Bb5+ Ke7 8.Bc5+
                                   Kf7 9.Kf5 Kg7 10.Be8 Kh7 11.Kf6 Kh6
                                   12.Bd4 Kh7 13.Be3 [>]
 106359465  28:    101.0  +Mat_20  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kc6 4.Ke4 Kd6
                                   5.Bc4 Kc6 6.Ke5 Kd7 7.Bb5+ Ke7 8.Bc5+
                                   Kf7 9.Kf5 Kg7 10.Be8 Kh7 11.Kf6 Kh6
                                   12.Bd4 Kh7 13.Be3 [>]
 126711350  29     120.2  +Mat_19  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Be4+
                                   Ke5 5.Bc5 Kf6 6.Kf4 Ke6 7.Bf3 Kd7 8.Ke5
                                   Kd8 9.Kd6 Ke8 10.Bh5+ Kf8 11.Ke6+ Kg7
                                   12.Be3 Kf8 13.Bh6+ Kg8 14.Bg6 Kh8
                                   15.Kf6 Kg8 [<]
 135650296  29:    128.5  +Mat_19  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Be4+
                                   Ke5 5.Bc5 Kf6 6.Kf4 Ke6 7.Bf3 Kd7 8.Ke5
                                   Kd8 9.Kd6 Ke8 10.Bh5+ Kf8 11.Ke6+ Kg7
                                   12.Be3 Kf8 13.Bh6+ Kg8 14.Bg6 Kh8
                                   15.Kf6 Kg8 [<]
 136893219  30     129.7  +Mat_19  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Be4+
                                   Ke5 5.Bc5 Kf6 6.Kf4 Ke6 7.Bf3 Kd7 8.Ke5
                                   Kd8 9.Kd6 Ke8 10.Bh5+ Kf8 11.Ke6+ Kg7
                                   12.Bf7 Kh6 13.Kf6 Kh7 14.Be3 Kh8 [<]
 142382101  30:    134.8  +Mat_19  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Be4+
                                   Ke5 5.Bc5 Kf6 6.Kf4 Ke6 7.Bf3 Kd7 8.Ke5
                                   Kd8 9.Kd6 Ke8 10.Bh5+ Kf8 11.Ke6+ Kg7
                                   12.Bf7 Kh6 13.Kf6 Kh7 14.Be3 Kh8 [<]
 144689826  31     137.0  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 149330487  31:    141.3  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 150763422  32     142.7  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 156629269  32:    148.2  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 178688284  33     168.8  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 187760101  33:    177.2  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 189231589  34     178.6  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 195859820  34:    184.7  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 197361375  35     186.1  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 204964850  35:    193.1  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 206476971  36     194.4  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 214600204  36:    201.8  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 216149217  37     203.2  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 223931424  37:    210.3  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 225750218  38     211.9  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 232985165  38:    218.4  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 235505688  39     220.6  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 244464068  39:    228.6  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 247629605  40     231.3  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 255122771  40:    238.1  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
 256632541  41     239.4  +Mat_17  1.Bd3 Ke5 2.Kg2 Kd6 3.Kf3 Kd5 4.Kf4 Ke6
                                   5.Bc4+ Kd6 6.Be3 Kc6 7.Ke5 Kd7 8.Bb5+
                                   Ke7 9.Bg5+ Kf7 10.Kf5 Kg7 11.Bc4 Kf8
                                   12.Kg6 Ke8 13.Bb5+ Kf8 14.Bc6 Kg8
                                   15.Bh6 Kh8 16.Bg7+ Kg8 17.Bd5#
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syzygy
Posts: 5696
Joined: Tue Feb 28, 2012 11:56 pm

Re: houdini3 search and mate scores

Post by syzygy »

michiguel wrote:Mate scores are a very special case of "scores" compared to +9.00 etc. The score per se is just "check mate", meaning, my side wins and the chances to win are 100%. However, since progress is needed, it contains an extra little piece of information, which is how distant that win is. That implies that the true meaning of a mate score is not "Mate in 10", but "Mate in 10 or better". From this perspective, Mate in 85 is not a wrong score.
I agree.
Traditionally, an engine always found shorter and shorter mates, and if it did not do that, some bug was present. With all the current pruning, not anymore. It is possible that a mate is detected, but later it is converted to a longer one (a defensive move was not pruned anymore).
Here I am a bit doubtful. I suppose most if not all engines do not prune moves that could defend against a mate score (or if they do, their authors would consider it a bug). The next ply finding only longer mates is probably the result of transposition table entries being overwritten. Another possibility is that for whatever reason the next ply reduces some moves more than the present ply (or prunes more moves from the winning side).
In Gaviota I worked a little bit about this but still these weird effects show up. The behavior is much better, but still there is a little hiccup going from mate in 24 to 25.
My engine happens to have no hiccups on this position. First mate in 20, then 19, 18, 17. But it is certainly not hiccup free in general.
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rabbits
Posts: 276
Joined: Wed Mar 08, 2006 10:14 pm
Location: Sydney, Australia

Re: houdini3 search and mate scores

Post by rabbits »

Chessmaster 10 announces mate in 17 in five seconds.
Al
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User avatar
Mike S.
Posts: 1480
Joined: Thu Mar 09, 2006 5:33 am

Re: houdini3 search and mate scores

Post by Mike S. »

From Houdini 1.5a(*) without Gaviotas, I got this:

Mate in 18 [+] 1. Bd3 Ke5 2. Kg2 Kd5 3. Kf3 Kd6 4. Ke4 Ke6 5. Bc4+ Kd6 6. Be3 Kd7 7. Ke5 Ke7 8. Bc5+ Kd7 9. Bb5+ Kc7 10. Ke6 Kc8 11. Kd6 Kd8 12. Bb6+ Kc8 13. Ba6+ Kb8 14. Bg1 Ka8 15. Kc6 Kb8 16. Kb6 Ka8 17. Bb7+ Kb8 18. Bh2# (depth 29, 0:01:26)
[+] Tablebase: 1.Bd3 - White wins in 17 moves

*) with internal 2.0c-settings, but that probably doesn't matter here
Regards, Mike
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