MadChess 3.0 Beta 2960ec9 (Bishop Pair)

I improved MadChess 3.0 Beta’s evaluation function by adding middlegame and endgame evaluation parameters for bishop pair. Tuning code indicated the bishop pair parameters immediately reduced evaluation error when examining a database consisting of approximately 54,000 Grandmaster games (both players 2600 ELO or stronger). I ran the Particle Swarm Optimization tuner on all evaluation parameters and it further reduced evaluation error. This improved evaluation function increased the playing strength of MadChess 3.0 Beta by 22 ELO.   Feature Category Date Commit1 WAC2 ELO Rating3 Improvement Bishop Pair Evaluation 2021 Mar 14 2960ec9 285 2592 +22 Position Cache Optimization Search 2021… Continue Reading

MadChess 2.0 Beta Build 069 (Bishop Pair)

I added bishop pair evaluation to MadChess 2.0 Beta. The code awards a bonus for possessing two or more bishops, calibrated by game phase. This added 18 ELO to the playing strength of MadChess 2.0 Beta. MadChess 2.0 2242 : 1280 (+561,=259,-460), 53.9 % vs. : games ( +, =, -), (%) : Diff, SD, CFS (%) Glass 1.6 : 80 ( 12, 12, 56), 22.5 : -219, 16, 0.0 RomiChess P3L : 80 ( 8, 12, 60), 17.5 : -215, 18, 0.0 OliThink 5.3.2 : 80 ( 7, 10, 63), 15.0 : -202, 18, 0.0 Myrddin 0.87 : 80 (… Continue Reading