Futility Pruning at Frontier Nodes

The well-known technique of futility pruning at frontier nodes (depth = 1) exploits the peculiarities of ``standing pat'' at horizon nodes (depth = 0). ``Standing pat'' means to compute the static evaluation score of a node in order to test it against the upper search bound for a possible fail-high beta cutoff without further lookahead. Thus, ``standing pat'' implements the null-move assumption during the quiescence search with static node evaluations serving as null-move scores of zero depth. The following two sections describe the theory and practice of futility pruning at frontier nodes in detail because they provide the foundations for our new pruning scheme.


Created by Ernst A. Heinz, Thu Dec 16 23:28:11 EST 1999