A Plausible Move Generator for Shogi Using Static Evaluation

Grimbergen, R. (1999)

in: Game Programming Workshop in Japan '99, pp. 9--15, Kanagawa, Japan

Abstract

To make a program that can perform well under tournament conditions, shogi poses some extra challenges when compared with chess. The main problem is that in shogi there are on average many more legal moves than in chess. To deal with this large branching factor, it seems inevitable to revive research into plausible move generators, which has not been successful in chess. In this paper a first step in developing a plausible move generator will be presented for moves involving winning and losing material. It will be explained how such a plausible move generator can use the static evaluation of shogi positions to generate moves. Test results show that this plausible move generator generates on average only 30% of the total number of moves. The time spent on this analysis is worth the effort, as is indicated by a major increase in performance on a test set of shogi problems. As preliminary results, these are very encouraging.