Humans see chess board as a Gestalt whole
Humans see a chess board as an organized pattern or Gestalt. Any move is part of the unfolding Gestalt pattern—and chess masters use pattern recognition to zero in on unprotected pieces and promising areas for attack or defence.
Past experiences and the history of the current game work together to build up an integrated awareness of "lines of force, the loci of strength and weaknesses, as well as specific positions" (Hubert Dreyfus, 1972, p. 105).
Note: Also see the "Can computers recognize Gestalts" arguments on Map 5.