Time-efficient state space search

Abstract

We present two time-efficient state space algorithms for searching minimax trees. Because they are based on SSS∗ and Dual∗, both dominate Alpha-Beta on a node count basis. Moreover, one of them is always faster in searching random trees, even when the leaf node evaluation time is negligible. The fast execution time is attributed to the recursive nature of our algorithms and to their efficient data structure (a simple array) for storing the best-first node information. In practical applications with more expensive leaf evaluations we conjecture that the recursive state space search algorithms perform even better and might eventually supersede the popular directional search methods.