The Guard Heuristic: Legal Move Ordering with Forward Game-Tree Pruning

Article type: Research Article

Authors: Ke, Yi-Fan | Parng, Tai-Ming

Affiliations: Department of Electrical Engineering, National Taiwan University

Abstract: A novel technique called the guard heuristic allows to achieve two purposes simultaneously, viz. pruning game trees and ordering legal moves. It is based on computing, for each square of the board in question, how well it is guarded by one’s own men and by those of one’s opponent Tests were run on Chinese chess, while the applicability to standard chess has been described in programmable detail. It seems that in chess the number of nodes visited is significantly reduced in comparison with other heuristics, without sacrificing move quality. Indications are that two or three ply suffice to produce a move for which other heuristics require up to six ply.

DOI: 10.3233/ICG-1993-16203

Journal: ICGA Journal, vol. 16, no. 2, pp. 76-85, 1993