[arvid]

From what I remember from Cognitive Psych class of late Bill Chase (CMU) 25 years ago. (great class because I still remember lots of it): Chess Masters divide a chess board into 6-7 patterns that fit into short term memory. They generally do not use depth first search. They usually immediately guess at 1-3 moves (most common was to look at only one move) and spend the rest of the time trying to verify the move(s). If you asked a chess master to memorize a chess board, remove the pieces then ask put them back. the chess master could always do it perfectly if the setup came from a real game. If the pieces were placed randomly, the chess master was no better than a normal person (basically could remember about 8 pieces).