Author: Robert Hyatt
Date: 12:35:45 06/13/04
Go up one level in this thread
On June 13, 2004 at 14:24:57, GeoffW wrote: >Hi > >I was thinking how I would add pawn hashing to my program. Having read a little >of the Crafty source I have a rough grasp of the idea, however there are a >couple of things I am hazy on. > >Q1) >I understand the pawn hash score stored must not contain any piece related >scoring as that must be factored in later. In my program even the simple choice >of which pawn position look up table is determined by the phase of the game, i.e >it will be piece dependent. How would I get over that obstacle ? Score the pawns >for end game, opening and middle in the hash, and choose which one to use later >? If you have to do that (phase of game) then that is one solution. > >Q2) >Crafty uses an 8 bit bitmap to store file for passers, this is ok for a bitboard >program as it is probably trivial to find the exact location later. However for >a non bitboard program it is non trivial to find the exact locations. Do I have >any alternative but to store the passer locations in the hash ? That would be 16 >bytes just for the passed pawns for both sides? 8 bits is not hard to use. It is not quite the same as "bitboard stuff" in reality... You simply have to do what works best. 1 byte per passed pawn is overkill, but it can work if memory is not an issue... > >Hope my questions made sense I typed them quickly as the England match is about >to start, must dash ................... > >Thanks for any help > > Regards Geoff
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.