Null Move And Deep Search - Selective-Search Heuristics For Obtuse Chess Programs

This article describes in detail a selective-search heuristic which uses a null-move approach recursively. A variety of empirical data, ranging from tournament results against strong human players to special test positions, are presented. These results do not falsify the hypothesis that the heuristic should be considered as a serious candidate for controlling the search process in a chess program.Most modem microcomputer chess programs use a mixed search strategy, consisting of a brute-force part to avoid shallow tactical blunders and a selective part designed to increase the efficiency of the search at greater search depths. The second part of our heuristic amounts to extending the search in forced positions, especially near the horizon.