FACTORS AFFECTING DIMINISHING RETURNS FOR SEARCHING DEEPER 1

Abstract

The phenomenon of diminishing returns for additional search effort has been observed by several researchers. We study experimentally additional factors which influence the behaviour of diminishing returns that manifest themselves in go-deep experiments. The results obtained on a large set of more than 40,000 positions from chess grandmaster games using the programs CRAFTY, RYBKA, and SHREDDER show that diminishing returns depend on (a) the values of the positions, (b) the quality of the evaluation function of the program used, and to some extent also on (c) the phase of the game, and the amount of material on the board.