Low Overhead Alternatives to SSS

Of the many minimax algorithms, SSS* is noteworthy because it usually searches the smallest game trees. Its success can be attributed to the accumulation and use of information acquired while traversing the tree. The main disadvantages of SSS* are its high storage needs and management costs. This paper describes a class of methods, based on the popular alpha-beta algorithm, that acquire and use information to guide a tree search. They retain a given search direction and yet are as good as SSS*, even while searching random trees. Further, although some of these new algorithms also require substantial storage, they are more flexible and can be programmed to use only the space available, at the cost of some degradation in performance. Acknowledgement Financial support from both the Natural Sciences and Engineering Research Council Grant A7902 and the Killam Exchange Scholarship Program, made it possible to complete the experimental work. Revised edition for Artificial Intelligence. Generated from files dated 9 October 1986. ______________________ The present address of Alexander Reinefeld is: Fachbereich Informatik, Universitaet Hamburg, Schlueterstrasse 70, D-2000 Hamburg 13, West Germany.