Author: Robert Hyatt
Date: 07:07:47 06/02/98
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On June 02, 1998 at 09:35:48, Roberto Waldteufel wrote: > > > >>OK. The Problem is the quiet search. I accept. >>Has anybody tried to learn the quiet search non qiet positions, and is >>the slow down worth? >> >>Werner > > >One thing that might be worth trying is to include promoting moves of >pawns, possibly even moves of a pawn to the seventh rank as well. I know >this has been implemented in some programs (eg Cray Blitz did this I >believe - probably also Crafty, but you'll have to ask Bob). I once >tried allowing the quiescence search to look at all moves of >"unstoppable" passed pawns, but this proved far too expensive to be >acceptable. It would solve your running pawn problem, though. I think it >might be possible provided that it was only done in a very small >proportion of positions - the trick is how to decide when "passed pawn" >quiescence is appropriate. Just like "check quiescence", this will blow >your search sky high if it is not accompanied by very strict conditions >for its applicaton. Maybe something could be done along the lines of a >smart preprocessing routine to try and determine if running pawns were >likely to be an issue within the search depth about to be done, but this >would be difficult to catch all cases. You could hope to weed out some >of them, though. Just an idea to kick around, I have not implemented >this myself, but it is on my "things to do" list. > >Roberto I did it in cray blitz, but I also flagged the resulting position as "must try all legal moves".. so that he couldn't "stand pat" and stop the forcing variation. Also, you have to worry about plies *before* this one as well, as if your opponent can stand pat, you can't force your passed pawn pushes to happen... I don't do it in crafty, however. Instead, I try to force extensions in the basic search, which is perfectly capable of handling this sort of stuff since there is no "qsearch stand-pat" problem to overcome or fake out. And the trick I did in Cray Blitz was very expensive...
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