Author: Ernst A. Heinz
Date: 07:42:20 11/03/98
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On November 02, 1998 at 17:19:56, Don Dailey wrote: >On November 02, 1998 at 04:49:55, Ernst A. Heinz wrote: > >>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= > >Hi Ernst, > >I think you are measuring something wrong. I don't think so (see my answer to Bob's other post). >What I do is more like Bobs technique, in fact my pawn structure >hashing does not even compute pawns structure scores but instead >returns lots of useful information to make extracting the scores >and many other piece interactions with pawns easy. Our hashed King-safety and Pawn-structure entries return much useful information, too, but they also return some raw scores. =Ernst=
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