Author: Robert Hyatt
Date: 13:01:08 07/09/99
Go up one level in this thread
On July 09, 1999 at 02:58:46, Richard A. Fowell (fowell@netcom.com) wrote: >On July 08, 1999 at 21:59:17, Jonathan Goldstein wrote: > >>After experimenting with board representaions for a few months, >>I found a representaion in which the move generator is slightly >>slower than rotated bitboards in the middlegame, but factors >>of 2 to 5 faster in the endgame (on a 32-bit processor). I >>decided to go with this representation, but it does have one >>drawback: Each side cannot have more than 8 of any piece. >> >>Is this a problem for normal (not wild) chess? At first I >>thought it couldn't possibly be, but then I considered if the >>engine ever gets fast enough to search 15 ply, and one of the >>extensions has the eighth pawn promoted, it could happen. Am I >>just being rediculous? :) >> >>-Jon > >Your in good company - some of the top commercial programs >can't handle this, either. > >It's a theoretical problem, but not much of a practical one. >In my 1300 tournament games, the largest number of any piece >I saw was five (bishops, as it turned out - my opponent was >trying to shame me into resigning). > >Maybe someone with a millionbase can comment on the maximum >number of each type of piece seen? > >-Richard Real positions don't matter here... it is "what can the search produce from the root to the tips?" that you have to deal with. _lots_ of strange things happen in a full-width search. While > 8 queens are not likely, I recently discovered a bug in my eval that would break if one side had > 4 queens, and they were all on the side of the board away from the kings. And this was in a _real_ game position that wasn't made up...
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.