Computer Chess Club Archives


Search

Terms

Messages

Subject: Questions about attack tables

Author: Scott Gasch

Date: 21:15:31 01/19/03


Hi all,

I'm pondering a major code overhaul of the engine to implement some ideas I've
been thinking about for a while.  One of these is attack tables.  So I wanted to
seek the advice of those of you who have attack tables in your engines already.

First, I assume attack tables are things you want to do incrementally.  This
seems really expensive though -- not only do you have to update the squares
attacked by the moving piece but also you have to look for attacks exposed by
the vacated square and attacks blocked by the destination square.  I'm not
missing any more clever way to handle this incrementally am I?

Next, on Ed's page he talks a little about attack tables in Rebel.  He said he
generates them non-incrementally (in eval from scratch) and he says he only uses
a few bits per side.  Like a single P, N, B, R, Q, K bit and a count.  I wonder
why not burn a few extra bits and have P, P, N, N, B, R, R, Q, K (10 total): it
would make the square control lookup table much more accurate and not too big (I
get 1M entries)?

Any feedback / advice appreciated.
Scott



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.