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
Feature | Category | Date | Rev1 | WAC2 | Elo Rating3 | Improvement |
---|---|---|---|---|---|---|
Passed Pawns | Evaluation | 2014 Dec 09 | 26 | 225 | 1766 | +72 |
Time Management | Search | 2014 Dec 08 | 25 | 231 | 1694 | +24 |
Delay Move Generation Aspiration Window Bug |
Search | 2014 Dec 02 | 23 | 231 | 1670 | +44 |
MVV / LVA Move Order Draw By Insufficient Material Move List Overflow Bug |
Search | 2014 Dec 01 | 22 | 235 | 1626 | +30 |
Tapered Evaluation MG and EG Piece Location |
Evaluation | 2014 Nov 29 | 21 | 234 | 1596 | +107 |
Alpha / Beta Negamax Aspiration Windows Quiescence, Hash Material, Piece Squares |
Baseline | 2014 Nov 25 | 20 | 236 | 1489 | – |
- Subversion source code revision
- Win At Chess position test, 3 seconds per position
- Bullet chess, 2 min / game + 1 sec / move