Problematic Positions and Speculative Play

Abstract

His basic idea was to accumulate various statistics about the search(like the number of fail-highs or fail-lows in an alpha-beta search) in order to extractsome meta-information about how the search progresses. In particular, he suggested tolook for trap and swindle positions, i.e., positions in which one of the opponent’smoveslooks much better (much worse) than its alternatives, assuming that the opponent’ssearch depth is limited. Trap positions have the potential that the opponent might makea bad move because its refutation is too deep in the search tree, while in a swindleposition the player can hope that the opponent overlooks one of his best replies becausehe does not see the crucial continuation.15 In subsequent work, Jansen (1992b, 1992a,1993) has investigated the use of heuristics that occasionally suggest suboptimal moveswith swindle potential for the weaker side of KQKR chess endgame.