Search heuristics of chess players of different calibers.

Information-processing models of chess-playing ability have distinguished between players of different calibers solely in terms of perceptual encoding and recognition of chess configurations. A reanalysis of deGroot's verbal protocols of 1965 indicates that players of different calibers direct their attention toward different areas of the board. Grandmasters and masters consider squares that are affected by many pieces, while lesser players direct their attention toward squares on which the pieces are located. In a recall experiment, chess positions were presented that had been randomly generated so as to differ only in the degree to which the pieces converge on the same squares. Masters showed superior recall for briefly presented positions only when the material affects a highly centralized area of the board.