Relationship between mis\`ere NIM and two-player GOISHI HIROI

Abstract

In combinatorial game theory, there are two famous winning conventions, normal play and mis\`ere play. Under normal play convention, the winner is the player who moves last and under mis\`ere play convention, the loser is the player who moves last. The difference makes these conventions completely different, and usually, games under mis\`ere play convention is much difficult to analyze than games under normal play convention. In this study, we show an interesting relationship between rulesets under different winning conventions; we can determine the winner of two-player GOISHI HIROI under normal play convention by using NIM under mis\`ere play convention. We also analyze two-player GOISHI HIROI under mis\`ere play convention.