The Principle of Pressure in Chess

This paper presents a new algorithm, \Pressure Search," for growing min-max game trees. The algorithm is based on the idea of best-rst search. The goal of the search is to nd a strategy which will change the estimated value of the current position. The amount of pressure, deened as inversely proportional to the number of options available to the opponent, is used as a heuristic measure of the remaining distance to the goal. Pressure Search has the potential to selectively extend parts of the search tree and thus discover deep combinations faster than standard alpha-beta search.