A Chess-Playing Program

Abstract

Computer chess programs have long been a testing ground for developing search techniques. Chess programs use some form of lookahead (prediction of future moves) search combined with static evaluation (judging the relative worth of a chess position without lookahead, that is by counting material worth of both black and white pieces and comparing the relative mobility of those pieces). We will develop a chess playing program in this chapter which relies mostly on static evaluation using heuristic chess knowledge. The program will usually give the impression of strong positional play although it plays a poor tactical game. The advantages of this heuristic approach (as compared to brute force search) are: faster execution in a LISP environment, easier to add and test new chess heuristics, and a simpler program. The static evaluation function, in calculating which pieces are subject to capture, effectively performs a two-ply (that is, half moves, by either the white or black pieces) lookahead search.