Author: Harald Lüßen
Date: 12:39:36 04/20/04
Go up one level in this thread
On April 20, 2004 at 12:52:47, Robert Hyatt wrote: >On April 20, 2004 at 11:50:29, Dieter Buerssner wrote: > >>On April 20, 2004 at 06:10:05, Omid David Tabibi wrote: >> >>>In his article "PEASANT: An endgame program for kings and pawns", Newborn >>>writes: "Position 70 would require a 30-ply search (25,000 hours)" >> >>I did the experiment. A search without transposition tables, without >>pruning/extensions and with material only eval (I forgot, if I used qsearch or >>not). A pawn capture was found at depth 26 (after 8 hours, IIRC). > >I assume you mean depth=26, not ply=26? IE white wins the pawn and I had >thought that this happens on ply=27, which means the first ply of q-search. > >I will try to run this myself as it would be nice to know exactly how deep this >is precisely, verified by multiple programs... > > >> With hash, it >>is almost guaranteed, that you find it at lower depth. Every second ply, you >>will have to search all moves, and many inferior moves will be refuted by seeing >>the pawn capture earlier. These refutations will be in the HT, and will be >>grabbed in the other more decent lines, to find the solution at lower depth. >> >>For my engine, even 1000 entries in the HT is enough, to solve the problem in >>practically no time. > >Theoretically if you search a perfectly ordered tree, the hash table should not >let you solve it at a shallower than normal depth, although it should cut the >time dramatically as we all see... > >> >>Regards, >>Dieter Another example: My engine Elephant found it at depth 19. The PV has 26 plies then but this may be accidental. Output: 1 144 0 3 Ka1-b2 Output: 2 130 0 12 Ka1-b2 Ka7-b6 Output: 3 145 0 34 Ka1-b2 Ka7-b6 Kb2-c3 Output: 4 144 0 103 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-b6 Output: 5 152 1 231 Ka1-b2 Ka7-b7 Kb2-c2 Kb7-b6 Kc2-d3 Output: 6 145 1 423 Ka1-b2 Ka7-b7 Kb2-c2 Kb7-c7 Kc2-d3 Kc7-d7 Output: 7 147 1 786 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c8 Kc3-d2 Kc8-d7 Kd2-e3 Output: 8 146 1 1131 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c8 Kc3-d2 Kc8-d7 Kd2-e3 Kd7-e7 Output: 9 153 1 1802 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Output: 10 153 1 2323 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Output: 11 153 3 2837 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Output: 12 153 3 3518 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Output: 13 153 4 4113 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Output: 14 153 4 4829 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Output: 15 153 4 5744 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Output: 16 153 6 6761 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Output: 17 153 6 8316 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Output: 18 153 7 10114 Ka1-b2 Ka7-b7 Kb2-c3 Kb7-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Kc7-b6 Kc4-c3 Kb6-c7 Kc3-c4 Output: 19 153 84 258286 Ka1-b2 Ka7-a8 Kb2-c3 Ka8-b7 Kc3-c4 Kb7-b6 Kc4-c3 Kb6-b7 Kc3-c4 Kb7-b6 Kc4-c3 Kb6-b7 Kc3-c4 Kb7-b6 Kc4-c3 Kb6-b7 Kc3-c4 Kb7-b6 Kc4-c3 Kb6-b7 Kc3-c4 Kb7-b6 Kc4-c3 Kb6-b7 Kc3-c4 Kb7-b6 B Output: 19 164 84 258951 Ka1-b1 Ka7-a8 Kb1-b2 Ka8-b7 Kb2-c3 Kb7-b6 Kc3-c4 Kb6-c7 Kc4-b5 Kc7-d7 Kb5xa5 Kd7-c8 Ka5-a6 Kc8-c7 Ka6-a5 Kc7-c8 Ka5-a6 Kc8-c7 Ka6-a5 Kc7-c8 Ka5-a6 Kc8-c7 Ka6-a5 Kc7-c8 Ka5-a6 Kc8-c7 Output: 19 160 162 546165 Ka1-b1 Ka7-a8 Kb1-b2 Ka8-b7 Kb2-c3 Kb7-b6 Kc3-c4 Kb6-c7 Kc4-b5 Kc7-d7 Kb5xa5 Kd7-c8 Ka5-a6 Kc8-c7 Ka6-a5 Kc7-c8 Ka5-a6 Kc8-c7 Ka6-a5 Kc7-c8 Ka5-a6 Kc8-c7 Ka6-a5 Kc7-c8 Ka5-a6 Kc8-c7 B Output: 20 170 200 670271 Ka1-b1 Ka7-a8 Kb1-b2 Ka8-b7 Kb2-c3 Kb7-b6 Kc3-c4 Kb6-c7 Kc4-b5 Kc7-d7 Kb5xa5 Kd7-e7 Ka5-a6 Ke7-f6 Ka6-a5 Kf6-e7 Ka5-a6 Ke7-f6 Ka6-a5 Kf6-e7 Ka5-a6 Ke7-f6 Ka6-a5 Kf6-e7 Ka5-a6 Ke7-f6 Ka6-a5 Output: 20 168 428 1458872 Ka1-b1 Ka7-a8 Kb1-b2 Ka8-b7 Kb2-c3 Kb7-b6 Kc3-c4 Kb6-c7 Kc4-b5 Kc7-d7 Kb5xa5 Kd7-e7 Ka5-a6 Ke7-f6 Ka6-a5 Kf6-e7 Ka5-a6 Ke7-f6 Ka6-a5 Kf6-e7 Ka5-a6 Ke7-f6 Ka6-a5 Kf6-e7 Ka5-a6 Ke7-f6 Ka6-a5 B Output: 21 178 912 3116631 Ka1-b1 Ka7-b7 Kb1-c2 Kb7-c8 Kc2-d2 Kc8-d7 Kd2-c3 Kd7-c7 Kc3-d3 Kc7-b7 Kd3-c3 Kb7-b6 Kc3-c4 Kb6-a6 Kc4-d3 Ka6-a7 Kd3-e3 Ka7-a8 Ke3-d2 Ka8-b7 Kd2-c3 Kb7-b6 Kc3-c4 Kb6-a6 Kc4-d3 Ka6-a7 Kd3-e3 Ka7-a8 Output: 21 202 1075 3710076 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c1 Kd8-e7 Kc1-d1 Ke7-f7 Kd1-d2 Kf7-g6 Kd2-c2 Kg6-f7 Kc2-d3 Kf7-g6 Kd3-c4 Kg6-h5 Kc4-b5 Kh5-g4 Kb5-c6 Kg4xf4 Kc6xd6 Kf4-e4 Kd6-c5 Output: 22 194 1087 3742585 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-e7 Kc2-d3 Ke7-f7 Kd3-c4 Kf7-g6 Kc4-b5 Kg6-h5 Kb5xa5 Kh5-g4 Ka5-b5 Kg4xf4 Kb5-c6 Kf4-e3 Kc6xd6 f5-f4 Output: 23 201 1101 3787840 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-c7 Kc2-d3 Kc7-d8 Kd3-c4 Kd8-e7 Kc4-b5 Ke7-f7 Kb5xa5 Kf7-g6 Ka5-b5 Kg6-h5 Kb5-c6 Kh5-g4 Kc6xd6 Kg4-f3 Kd6-e7 Kf3xf4 d5-d6 Kf4-e4 d4-d5 Output: 24 202 1146 3933077 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-c7 Kc2-d3 Kc7-d8 Kd3-c4 Kd8-c7 Kc4-b5 Kc7-d8 Kb5xa5 Kd8-e7 Ka5-b5 Ke7-d7 Kb5-a5 Kd7-c7 Ka5-b5 Kc7-d7 Kb5-a5 Kd7-c7 Ka5-b5 Kc7-d7 Kb5-a5 Kd7-c7 Ka5-b5 Kc7-d7 Kb5-a5 Output: 25 203 1206 4142744 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-c7 Kc2-d3 Kc7-d8 Kd3-c4 Kd8-c7 Kc4-b5 Kc7-d8 Kb5xa5 Kd8-e7 Ka5-b5 Ke7-f6 Kb5-a5 Kf6-g6 Ka5-b5 Kg6-h5 Kb5-a5 Kh5-g4 Ka5-b5 Kg4-f3 a4-a5 Kf3xf4 a5-a6 Kf4-e4 Kb5-a5 Ke4-e3 Output: 26 203 1592 5447916 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-d7 Kc2-c3 Kd7-c7 Kc3-d3 Kc7-d8 Kd3-c4 Kd8-c7 Kc4-b5 Kc7-d8 Kb5xa5 Kd8-c7 Ka5-b5 Kc7-d8 Kb5-a5 Kd8-c7 Ka5-b5 Kc7-d8 Kb5-a5 Kd8-c7 Ka5-b5 Kc7-d8 Kb5-a5 Kd8-c7 Ka5-b5 Kc7-d8 Kb5-a5 Output: 27 204 1651 5646445 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-d7 Kc2-c3 Kd7-c7 Kc3-d3 Kc7-d8 Kd3-c4 Kd8-d7 Kc4-b5 Kd7-c7 Kb5xa5 Kc7-d8 Ka5-b5 Kd8-e7 Kb5-a5 Ke7-f6 Ka5-b5 Kf6-g7 Kb5-a5 Kg7-h7 Ka5-b5 Kh7-h6 Kb5-a5 Kh6-h5 Ka5-b5 Kh5-g4 a4-a5 Kg4xf4 Output: 28 204 2370 8061562 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-c7 Kc2-d3 Kc7-d8 Kd3-c4 Kd8-d7 Kc4-b5 Kd7-c7 Kb5xa5 Kc7-d8 Ka5-b5 Kd8-d7 Kb5-a5 Kd7-e7 Ka5-b5 Ke7-f6 Kb5-a5 Kf6-g7 Ka5-b5 Kg7-h7 Kb5-a5 Kh7-g6 Ka5-b5 Kg6-h5 Kb5-a5 Kh5-g4 Ka5-b5 Kg4-f3 a4-a5 Output: 29 207 3318 11379129 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-c7 Kc2-d3 Kc7-d8 Kd3-c4 Kd8-c7 Kc4-b5 Kc7-d8 Kb5xa5 Kd8-d7 Ka5-b5 Kd7-e8 Kb5-a5 Ke8-f7 Ka5-b5 Kf7-g6 Kb5-a5 Kg6-h5 Ka5-b5 Kh5-g4 a4-a5 Kg4xf4 a5-a6 Kf4-e4 Kb5-a5 Ke4-f4 Ka5-b5 Kf4-e4 Kb5-a5 Ke4-f4 Output: 30 209 4692 16012949 Ka1-b1 Ka7-b7 Kb1-c1 Kb7-c7 Kc1-d1 Kc7-d8 Kd1-c2 Kd8-c7 Kc2-d3 Kc7-d8 Kd3-c4 Kd8-c7 Kc4-b5 Kc7-d8 Kb5xa5 Kd8-d7 Ka5-b5 Kd7-e8 Kb5-a5 Ke8-f7 Ka5-b5 Kf7-g6 Kb5-a5 Kg6-h5 Ka5-b5 Kh5-g4 a4-a5 Kg4-f3 a5-a6 Kf3xf4 Kb5-a5 Kf4-f3 Ka5-b5 f5-f4 Kb5-a5 Kf3-e4 a6-a7 Unfortunately today I have a bug in the current version of the engine and it only shows (repetition-)draws at horrible search depths. :-( Harald
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