MadChess 2.0 Beta Build 026 (Passed Pawns)

I added passed pawn evaluation to MadChess 2.0 Beta. No sophisticated evaluation of free (unimpeded) or unstoppable passed pawns. Just a simple tapered evaluation of passed pawns, with a score based on the pawn’s rank.

This added 72 Elo to the playing strength of MadChess 2.0 Beta.

Bug

While watching one of the games, I observed MadChess play a losing move in a drawn by repetition position. It gave a score of mate in zero (which is nonsense), searched to the max depth of 100 plies. I need to hunt down this bug, which likely is robbing MadChess of significant Elo.

MadChess 2.0                   1766 :    800 (+151,=49,-600),  21.9 %

vs.                                 :  games (   +,  =,   -),   (%) :   Diff,  SD, CFS (%)
BikJump v2.01                       :    100 (   6,  5,  89),   8.5 :   -320,  14,    0.0
Matheus-2.3                         :    100 (   8,  2,  90),   9.0 :   -304,  14,    0.0
Monarch 1.7                         :    100 (  10, 11,  79),  15.5 :   -273,  15,    0.0
BigLion 2.23w                       :    100 (  16,  9,  75),  20.5 :   -243,  13,    0.0
Faile 1.4                           :    100 (  17,  3,  80),  18.5 :   -234,  12,    0.0
Sharper 0.17                        :    100 (  27,  8,  65),  31.0 :   -219,  14,    0.0
Jabba13032012                       :    100 (  31,  5,  64),  33.5 :   -162,  13,    0.0
Roce 0.0390                         :    100 (  36,  6,  58),  39.0 :    -88,  12,    0.0

1. Subversion source code revision
2. Win At Chess position test, 3 seconds per position
3. Bullet chess, 2 min / game + 1 sec / move