Author: Martin Giepmans
Date: 12:20:35 03/31/03
Go up one level in this thread
On March 31, 2003 at 14:35:48, Uri Blass wrote: >Today latest movei evaluates passed pawns and protected passed pawns based on >the ranks of the pawn(I will later change it to evaluate them >based on other factors like square of the kings). > >The problem is that the order of evaluation is not correct. > >If I have a pawn at b5 and another passed pawn at c5 then >I want to evaluate them as better than pawn at b4 and >protected passed pawn at c5. > >I thought to give a bonus for passed pawn that has pawn in the left side of it >but the problem is that in that case the evaluation is not >symmetric and in the folowing diagram if the black pawn is in c6 and not f6 >I get different result. I think giving bonus/2 if there is a pawn on the right OR on the left side would do the trick. It's symmetrical. > > >[D]8/7k/5p2/8/3PP3/8/8/K7 w - - 0 1 > > >Another problem is what to do when there are 3 passed pawns. > >[D]8/7k/8/8/3PPP2/8/8/K7 w - - 0 1 > >In that case even if I decide to give only one bonus for pair >I may get here 2 bonuses and after the central pawn progress >one square forward I will have only one bonus. > >I wonder how other programs solve that problem. > >protected passed pawns are good but other things are also good and the problem >is how to order the things in the right order. > >Uri In my engine I give a bonus for a passed pawn that is (a) protected by a pawn (left or right) or (b) has a pawn on the left or on the right If both are not true (pawn is not protected and has no neighbor) I give a small penalty. The penalty is so small that it will not hinder the advance of the passed pawns. But it helps the engine to keep it's pawns "together". Cheers, Martin
This page took 0.01 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.