Author: Russell Reagan
Date: 11:28:28 01/24/02
Go up one level in this thread
On January 24, 2002 at 14:05:54, Leen Ammeraal wrote: >In an evaluation function, it makes sense to count >and reward attacks to occupied and free squares. >However, this can be done in several ways. >Currently, I have the following data available >and I assign bonus points for all these three >count results: > >a. counting each square that I attack > at most once, regardless of the number of > attackers and defenders for that square. > >b. counting all my attacks to squares, so this > count is 2 for a square if both my knight and > my bishop (and no other pieces of mine) attack it. > >c. counting all squares that I control in the > sense that I attack it with a given piece > and the opponent defends it only with > more expensive pieces. For example, I regard > a square in my control if I attack it with a pawn > (and possibly other pieces as well), while the > opponent may defend it with as many > non-pawn pieces as he likes. > >If you have a opinion (preferably based on experience >and chess knowledge) about the relative merits of >these counts in an eval function, please indicate >this by giving weight factors. >For example: >c 3, a 1, b 0 (if you regard b as useless). >(I hope your answer will not be a 0, b 0, c 0 -;) > >Leen A quote from http://www.gamedev.net/reference/programming/features/chess6/page2.asp "CHESS 4.5's creators estimate that an enormous advantage in position, mobility and safety is worth less than 1.5 pawns." I myself don't have very much experience with evaluation functions, but I would estimate: a 0, b 0, c 1. Where the 1 is about a pawn when you have a dominant advantage in c. In other words, I'd say it's close to a scale between -1 and +1 based on whether c is an advantage or disadvantage to you, and to what degree. I've heard chess masters say that mobility is the second most important factor in positional evaluation to material, generally speaking. Of course if you're Tal then material considerations go out the window :) Russell
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.