Author: Dann Corbit
Date: 16:10:58 11/15/04
Go up one level in this thread
On November 15, 2004 at 18:30:02, Wayne Lowrance wrote: >On November 15, 2004 at 16:40:47, Uri Blass wrote: > >>On November 15, 2004 at 15:57:23, Gerd Isenberg wrote: >> >>>Hi, >>> >>>i use the difference of weighted pawnbitboards ( 5*whitepawnBB - 3*blackpawnBB ) >>>mod 65077 as an index for a 64K entry pawnhash-table. Most often my pawnhash >>>hit-rate is quite ok, > 95% or even 99%. But it seems that a lot of pawn levers >>>decrease my hit-rate due to collisions. >>> >>>With "maximum lever" positions my pawnhash hit-rate is only about 75% after a 30 >>>second search on my amd64 2.2GHz box (~80% without eval hashing). >>> >>>I guess a zobrist-key pawn-hashing scheme is better here. >>>Curious about your pawnhash hit-rates with one of the positions below. >> >>I have no pawn hash tables so I have no pawn hash hit rates. >>The only pawn information that I calculate and use is passed pawns,isolated >>pawns and protected passed pawns and I do not know what is pawn levers. >> >>I do not use hash to store the information because I found that pawn hash does >>not change much for me and updating the bitboards incrementally is about the >>same speed as storing the information in hash so I decided to go for the simple >>solution. >> >>Uri > >Yea, what the heck is a pawn lever ? http://members.aol.com/manusfealy2/ch18.htm http://chess.about.com/od/reference/qt/bltip022.htm http://info.ex.ac.uk/~dregis/DR/glossary.html http://www.chess-dictionary-chesmayne.net/Glossary%20P.htm
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