GO-MOKU SOLVED BY NEW SEARCH TECHNIQUES

Many decades ago, Japanese professional Go-Moku players stated that Go -Moku (five-in-a-row on a horizontally placed 15 x 15 board) is a won game for the player to move first. So far, this claim has never been s ubstantiated by (a tree of) variations or by a computer program. Meanw hile, many variants of Go-Moku with slightly different rules have been developed. This paper shows that for two common variants, the game-th eoretical value has been established. Moreover, the Go-Moku program Vi ctoria is described. It uses two new search techniques: threat-space s earch and proof-number search. One of the results is that Victoria is bound to win against any (optimal) counterplay if it moves first. Furt hermore, it achieves good results as a defender against nonoptimally p laying opponents. In this contribution we focus on threat-space search and its advantages compared to conventional search algorithms.