New advances in alpha-beta searching

Abstract

Alpha-Beta has been the algorithm of choice for game-tree search for over three decades. Its success is largely attributable to a variety of enhancements to the basic algorithm that can dramatically improve the search efficiency. Although state-of-the-art game-playing programs build trees that are close in size to the minimal Alpha-Beta search tree, this paper shows that there is still room for improvement. Three new enhancements are presented: best-first Alpha-Beta search, better use of transpositions, and improving aspiration search under real-time constraints. Measurements show that these improvements can reduce search effort by 35%.