Author: Uri Blass
Date: 02:11:41 09/21/03
Go up one level in this thread
On September 21, 2003 at 01:00:37, Paul Byrne wrote: >I read the thread on the pawn game last night... >http://www.talkchess.com/forums/1/message.html?316441 > >...and added it as a variant to Guildenstern (which is pretty basic >as chess engines go, but is set up to handle rules variations like >this -- first version took about 10 minutes). The first version >called it a win when a pawn hit the 7th rank; changing this to >getting a passed pawn more advanced than the opponent's most advanced >pawn (passed or not) caused a speedup of about 100x in solving the >couple of test positions I was using. > >Anyways, to give you an idea how solvable this game is or isn't, >I left it running on this position last night: > >[D]8/1pppppp1/8/p6p/P6P/8/1PPPPPP1/8 w - - 0 3 > >with this result: > >mv=g4 e=12 d=1 n=14 t=0.000 >mv=f4 e=0 d=2 n=104 t=0.000 >mv=f4 e=12 d=3 n=371 t=0.002 >mv=f4 e=0 d=4 n=870 t=0.002 >mv=f4 e=12 d=5 n=2859 t=0.006 >mv=f4 e=-7 d=6 n=7296 t=0.013 >mv=f4 e=12 d=7 n=17061 t=0.028 >mv=f3 e=-4 d=8 n=56297 t=0.128 >mv=f4 e=19 d=9 n=152838 t=0.351 >mv=f4 e=-7 d=10 n=253530 t=0.586 >mv=e4 e=19 d=11 n=718726 t=1.473 >mv=e4 e=-2 d=12 n=1169031 t=2.114 >mv=e4 e=19 d=13 n=1875217 t=3.137 >mv=e4 e=-2 d=14 n=3304028 t=5.235 >mv=e4 e=16 d=15 n=6028707 t=9.264 >mv=e4 e=0 d=16 n=14889769 t=22.461 >mv=e4 e=28 d=17 n=116308613 t=168.791 >mv=e4 e=0 d=18 n=277650527 t=400.234 >mv=e4 e=27 d=19 n=493734227 t=706.427 >mv=e4 e=0 d=20 n=830582334 t=1181.929 >mv=e4 e=14 d=21 n=1572079524 t=2209.587 >mv=e4 e=0 d=22 n=-989389009 t=4577.107 >mv=e4 e=32 d=23 n=1675198974 t=8170.032 >mv=e4 e=273 d=24 n=1318190910 t=13610.508 >mv=e4 e=9969 d=25 n=-1677339015 t=26967.618 > >So about 7.5 hours to solve this. one question: Did you use hash tables? some observations: 1)your nps is very slow only 400Knodes per second 2)There is a lot more to evaluate like unstoppable pawn majority and unstoppable pawns even in case that the opponent has more advanced pawn The following position can evaluate as win for black or win for white by a good evaluation. [D]8/p3p3/P6p/8/8/8/4P3/8 w - - 0 1 [D]8/p3p3/7p/PP6/8/8/4P3/8 w - - 0 1 My guess is still that it can be solved without hash. Uri
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