Author: Kai Skibbe
Date: 03:58:55 06/01/00
Today an experimental fritz engine of Gromit3 reaches the following
position against Junior6.
[D]1r6/5B2/n2n4/PN4kp/4P3/8/1K6/R7 w - - 0 48
Here Gromit plays the move Bxh5 with an evaluation of +0.48. Junior says
-5,09 in favour of black. After Rxb5+ Kc3 Kxh5 white is totally lost.
I remember that I have implemented the evaluation code for bad trades
similar to crafty and so it isn´t surprising that Crafty also want to play
Bxh5 with a slightly negative evaluation (-0,28). The code in Crafty is :
if (WhiteMinors != BlackMinors) {
if (WhiteMajors == BlackMajors) {
if (WhiteMinors > BlackMinors) {
if (WhiteMajors==1 && !TotalWhitePawns && TotalBlackPawns) {
score=0;
break;
The last if-condition should be :
if( WhiteMajors==1 && !TotalWhitePawns && TotalBlackPawns &&
1==(WhiteMinors-BlackMinors) )
So the materialscore isn´t set to 0, if one side is more than one minor up.
Now Gromit didn´t play Bxh5 and after Bxh5 Gromit says -4,45 in favour for
black.
Bob, am I missing something or is this a bug in the crafty code ?
Best regards
Kai
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