First experimental results of ProbCut applied to chess

Abstract

ProbCut is a selective-search enhancement to the standard alpha-beta algorithm for two-person games. ProbCut and its improved variant Multi-ProbCut (MPC) have been shown to be effective in Othello and Shogi, but there had not been any report of success in the game of chess previously. This paper discusses our implementation of ProbCut and MPC in the chess engine CRAFTY. Initial test results suggest that the MPC version of CRAFTY is stronger than the original version of CRAFTY: it searches deeper in prornising lines and defeated the original CRAFTY +22-10 = 32 (59.4%) in a 64-game match. Incorporating MPC into CRAFTY also increased its toumament performance against YACE - another strong chess program: CRAFTY's speed chess toumament score went up from 51% to 56%. © 2004 by Springer Science+Business Media New York.