Pathology in heuristic search

Abstract

Practice shows that game-playing programs using minimax search perform better when searching deeper. Mathematical analyses, however, showed the opposite. This paradox was termed minimax pathology. Our real-valued minimax model demonstrates that appropriate modeling of the heuristic error is enough to eliminate the pathology. We examine the conditions under which the pathology appears and explain the mechanism that makes minimax otherwise beneficial. The reasons for the pathology in single-agent search are also addressed.