MChess Pro is the name given to a chess playing computer program written by Marty Hirsch which won the World Microcomputer Chess Championship in 1995.[1] The program is no longer under development and is no longer commercially available[2] and therefore has largely historical significance only.
History
The versions of MChess Pro which appear on the historical and current SSDF ratings lists include 3.12, 3.5, 4.0, 5.0, 6.0, 7.1, and 8.0.[3][4]
Features
MChess Pro has its own DOS GUI and as well as playing chess is able to analyse EPD (Extended Position Description) files.[5] The opening book for the software is written by Sandro Necchi.[6]
Playing style
MChess Pro's style of play is designed to be particularly human, and, more specifically, particularly positional.[7] MChess Pro uses 'complex pattern recognition', has an evaluation function designed to focus on positional factors, and uses aggressive variation pruning in its searches.[1]
Playing strength
MChess Pro was one of the strongest chess programs of the 1990s.[1] MChess Pro finished 8th and was the highest placed computer in the 1991 AEGON Man-Machine tournament.[8] In the 10th AEGON event at the Hague in 1995, MChess Pro defeated three grandmasters[9] and achieved a performance rating of 2652 Elo.[10] MChess Pro has defeated a number of very strong players including Christiansen, Z. Polgar, Rohde, Shabalov, Cifuentes and Wolff.[10] By the end of the 1990s MChess Pro was slipping further down the SSDF (Swedish Chess Computer Association) rating lists and by 2001 was already outside the top 30 programs.[11]
This game from 1995 sees MChess Pro defeating one of the strongest female players of the 20th Century - Grandmaster Zsuzsa Polgar. Black suffers damage to her pawn structure early on and in the endgame allows an exchange of dark-squared bishops which leaves her king placed too passively. MChess Pro handles this endgame fairly well.