Author: scott farrell
Date: 23:15:27 06/21/03
Go up one level in this thread
On June 22, 2003 at 00:51:25, Robert Hyatt wrote: I moved them to evalKing, and cached passedPawnFiles into the pawn cache, as they are a little expensive to work out all the time. Scott >On June 21, 2003 at 22:48:01, scott farrell wrote: > >>I have had pawn hashtables for sometime, here is what I currently hash: >> >>- pawns >>- castling rights >> >>I store: >>- score >>- pawnattacks (my engine is bitboard based, so this is a bit board for >>sidetomove) >> >>This is fine for pawn only eval, passed, connected passed, doubled, etc etc. And >>if you take these pawn-only scenarios, I get 99% hash hit, and no collisions >>(more or less). >> >>My question goes to when you need to include other factors to score pawns >>effectively, like: >>- the king position and amount of other material for passed pawn races >>- the king position for passed pawns, if the king can protect the passed pawn, >>then it is more valuable. > >If you include other pieces, you have to hash them into the signature. This >will kill that 99%. I don't do it myself. For anything other than pawns, >I do that pawn scoring _after_ the hashing has been done. > > > > >> >>Now if you dont hash the "other info" like King position, I assume you have a >>nice new bug. If you do hash it, it ends up storing more info, and slowing, more >>collisions and less hits in % terms, and the incremental hashkey generation >>becomes more complex each time. >> >>What do other people do? >> >>Do you put king protecting passedpawns in the evalKing routine instead? > >You certainly should have it outside the pure pawn code, yes. > > > >> >>What about passed pawn races? Do you try to put that in evalking? > >that is essential, yes.
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.