Author: Ernst A. Heinz
Date: 01:49:55 11/02/98
Go up one level in this thread
On November 01, 1998 at 23:46:42, Robert Hyatt wrote: > >On November 01, 1998 at 13:47:18, Ernst A. Heinz wrote: > >>On November 01, 1998 at 12:56:12, Inmann Werner wrote: >>> >>>you are right. my percentage is about 50% in normal game. I have to think about >>>it. >>>On the one hand, if I make a hit, the evaluation is extremly fast. On the other >>>hand, if I only hash the pawns, I get much more hits, but have more to do in >>>much more difficult in evaluation, because good king standing and rook standing >>>depends on pawn structure. >>>When I have a little time, I try both and look whats really faster. >> >>Werner, >> >>All pieces that tend to move around *frequently* will greatly hurt the hit rate >>of your Pawn hashing. Therefore, I recommend that you never include any major >>or minor pieces therein. The Kings, however, are different "animals" which can >>safely be hashed together with the Pawns as long as they must stay behind safe >>shelters in the middlegame. "DarkThought" drops them from the Pawn hashing >>*dynamically* as soon as King safety does not matter anymore. >> >>=Ernst= > > >I did this in Cray Blitz, but believe that the current scheme I use in Crafty >is far better. With the king included my hash hits were in the 90% range or >so, while with it out, 99.9% is common. I looked at what I was doing, and >it was mainly king safety related. And the king safety with the king at g1 >is no better/worse than the king safety with the king at h1 or h2, if you only >look at pawns. I now do normal pawn scoring, then king safety on *both* sides >of the board, and store all this with just the pawn hash signature. When I >want >to evaluate king safety, I look at which side the king is on and start with >that >raw pawn structure score around the king... and then factor in other things >(like is there a queen, how close are the pieces, are there open files with >rooks on them around the king) and so forth.. > >I now get 99.9% hash hits which covers the king safety pawn structure... and >there's no loss in accuracy of any kind... We must be doing something right then because we also get more than 99% hit rates with the King factored in. :-) =Ernst=
This page took 0.01 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.