From his plaque at the Baseball Think Factory Hall of Merit:
He was a cat on his feet, a sure fielder and one of the quickest thinking players of his day. He was always a step ahead of the opposition. . . . There was never a player with keener intuition than Dahlen nor more capable of carrying out his intentions.
I should add that seven of the ten most similar players to him as determined by baseball-reference.com are in the Hall.
He made his real mark with his exceptional range, arm and quickness at short. He led shortstops in his league in assists 4 times and double plays 3 times. . . Retired with the shortstop major league career records for games (2,132), putouts (4,850), assists (7,500), and double plays (881). 2,457 career hits, 1,589 runs scored. Career OWP .577.