Author: Robert Hyatt
Date: 12:39:27 11/21/02
Go up one level in this thread
On November 21, 2002 at 12:39:24, Matthias Gemuh wrote: >On November 21, 2002 at 11:07:38, Robert Hyatt wrote: > >>On November 21, 2002 at 08:26:48, Matthias Gemuh wrote: >> >>>On November 21, 2002 at 08:15:50, Georg v. Zimmermann wrote: >>> >>>>On November 21, 2002 at 07:13:10, Vladimir Medvedev wrote: >>>> >>>>>depth = 9, from initial position: >>>>> >>>>>pawn hash = 1 entry -- 28% successful hits >>>>>2 -- 33% >>>>>3 -- 37% >>>>>4 -- 38% >>>>>5 -- 41% >>>>>7 -- 43% >>>>>10 -- 45% >>>>>100 -- 60% >>>>>... >>>>>65K -- 84% >>>>> >>>>>I was quite surprised with this :) >>>>>Even 1-node pawn "hash" helps a lot! >>>> >>>>Doesnt one get something around 99% with big tables ? >>> >>> >>> >>>With 2x65kB. More is not needed, if only pawns are considered. >> >> >>There are more possible pawn positions than that. White has 8, black has 8. >>there are >>48 possible squares any of them can be on... That is a pretty big number. > > > >Some hasty and wrong thinking then, when I implemented my pawn hash. >Maybe I somehow excluded strange positions like all pawns on 2nd and 3rd rows. >I shall check my code and logic later. >I generate keys such that they lie in range 1..2x64kB and use them as index. >I hit 95%..99% in middle game and WAC. > >Thanks, >Matthias. > >Thanks, >Matthias. Just one white pawn gives you 48 different positions. one white pawn and one black pawn gives you 48*48 different positions. or, rounding down a bit, 48 could be replaced by 2^5 (32). 48*48 could be approximated by 2^10 or 1024. two more pawns and we are going to blow past 64K positions.
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.