Theme detection and evaluation in chess

Abstract

Chess themes such as the fork and pin are essentially good tactics when playing the game of chess. The themes also form the underlying ideas behind chess compositions. In computational aesthetics, they are particularly important because the goal is shifted from game-playing to the evaluation of beauty. In this paper we propose formalizations for a selection of themes that can replace the traditional approach of attributing fixed values using the notions 'more flexible' and 'dynamic'. The main advantage of the formalization is that varying implementations of a theme can be weighted accordingly in a consistent fashion based on established chess metrics. Computational recognition and assessment of beauty in chess, whether in real games or compositions, can therefore be improved. For testing purposes we developed the program CHESTHETICA. Several experiments using a particularly designed computer program and thousands of chess combinations were performed to test the formalizations. The results are promising.