Heuristic search in one and two player games

Abstract

With the continuing price-performance improvement of small computers there is growing interest in looking again at some of the heuristic techniques developed for problemsolving and planning programs, to see if they can be enhanced or replaced by more algorithmic methods. The application of raw computing power, while and anathema to some, often provides better answers than is possible by reasoning or analogy. Thus brute force techniques form a good basis against which to compare more sophisticated methods designed to mirror the human deductive process. One source of extra computing power comes through the use of parallel processing on a multicomputer, an so this aspect is also covered here. Here we review the development of heuristic algorithms for application in singleagent and adversary games. We provide a detailed study of iterative deepening A * and its many variants, and show howe ective various enhancements, including the use of refutation lines and a transposition table, can be. For adversary games a full review of improved versions of the alpha-beta algorithm (e.g. Principal Variation Search) i