Author: Bert van den Akker
Date: 11:58:48 09/12/99
Go up one level in this thread
On September 12, 1999 at 06:43:49, leonid wrote: >On September 11, 1999 at 22:09:38, Bas Hamstra wrote: > >>HashTables are very important for movesorting. Best moves from previous searches >>are in the hashtable. That way you can very much improve the probability that >>you play the best move first, which is immensely important for the alpha-beta >>scheme. When you search to ply n with hashtables you have to examine less nodes >>than without, because of that. >> >>Estimates of how much less vary from 20% to 50%. In case of 50%, assuming using >>nullmove, yes that is almost a ply. >> >> >>Regards, >>Bas Hamstra. > >Your message, and the one above, is more that useful. This is just moves >ordering that still must be improved in my game and, after what I can see, >hash table help even in this aspect. When I tryed my engin against the best >one my "branching factor" was miserable. Now I work in improving it. > >With my respect, >Leonid. With my program I have done the following test on position: 2r1r1k1/3p1p1p/p2Qp1p1/q1N2P2/Pn1B1P2/6P1/2P3bP/2KRR3 b - - to see what is the influence of Hash tables, Null move and History tables on the search time. All times are in seconds. D=Queen T=Rook L=Bishop P=Night With Hash table: 524288 entries Recursive Null move: R=2 History table for move ordering: On Depth Score Time_for_ply Time_PV PV 1 -223 0 0 Tc8-b8 2 -196 0 0 Tc8-b8 Kc1-d2 e6xf5 Te1xe8+ Tb8xe8 Dd6xd7 3 -192 2 2 g6xf5 Dd6xd7 4 -154 4 1 g6xf5 Dd6-e5 f7-f6 De5xf6 5 -195 13 8 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ c2-c4 Db4xc4+ Ka2-a3 6 -289 9 1 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 Te1xe8+ Tc8xe8 c2-c3 7 -282 25 5 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 8 -277 115 18 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 total time 168 With Hash table: Off Recursive Null move: R=2 History table for move ordering: On Depth Score Time_for_ply Time_PV PV 1 -223 0 0 Tc8-b8 2 -196 0 0 Tc8-b8 Kc1-d2 e6xf5 Te1xe8+ Tb8xe8 Dd6xd7 3 -192 3 2 g6xf5 Dd6xd7 4 -154 3 0 g6xf5 Dd6-e5 f7-f6 De5xf6 5 -195 18 11 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ c2-c4 Db4xc4+ Ka2-a3 6 -289 34 6 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 Te1xe8+ Tc8xe8 c2-c3 7 -282 79 19 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 8 -277 324 76 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 total time 461 With Hash table: 524288 entries Recursive Null move: Off History table for move ordering: On Depth Score Time_for_ply Time_PV PV 1 -223 0 0 Tc8-b8 2 -196 0 0 Tc8-b8 Kc1-d2 e6xf5 Te1xe8+ Tb8xe8 Dd6xd7 3 -192 2 2 g6xf5 Dd6xd7 4 -154 4 1 g6xf5 Dd6-e5 f7-f6 De5xf6 5 -195 16 11 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ c2-c4 Db4xc4+ Ka2-a3 6 -289 35 4 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 Te1xe8+ Tc8xe8 c2-c3 7 -282 145 26 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 8 -277 808 110 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 total time 1010 With Hash table: 524288 entries Recursive Null move: R=2 History table for move ordering: Off Depth Score Time_for_ply Time_PV PV 1 -223 0 0 Tc8-b8 2 -196 0 0 Tc8-b8 Kc1-d2 e6xf5 Te1xe8+ Tb8xe8 Dd6xd7 3 -192 2 2 g6xf5 Dd6xd7 4 -154 4 1 g6xf5 Dd6-e5 f7-f6 De5xf6 5 -195 14 8 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ c2-c4 Db4xc4+ Ka2-a3 6 -289 10 1 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 Te1xe8+ Tc8xe8 c2-c3 7 -282 29 5 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 8 -277 113 19 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 total time 172 With Hash table: 2097152 entries Recursive Null move: R=2 History table for move ordering: On Depth Score Time_for_ply Time_PV PV 1 -223 0 0 Tc8-b8 2 -196 0 0 Tc8-b8 Kc1-d2 e6xf5 Te1xe8+ Tb8xe8 Dd6xd7 3 -192 2 1 g6xf5 Dd6xd7 4 -154 3 0 g6xf5 Dd6-e5 f7-f6 De5xf6 5 -195 14 8 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ c2-c4 Db4xc4+ Ka2-a3 6 -289 9 1 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 Te1xe8+ Tc8xe8 c2-c3 7 -282 25 6 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 8 -277 109 18 Pb4-a2+ Kc1-b2 Da5-b4+ Kb2xa2 Lg2-d5+ Dd6xd5 e6xd5 c2-c3 Db4-c4+ Ka2-a3 d7-d6 Pc5-b7 total time 162 Bert van den Akker
This page took 0 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.