If you want to be a good bowler, get your own ball and get one that's right for you. That's one secret of expert bowling, a secret often overlooked. If you flit from a ball with a two-finger grip to one with a three-finger grip, from a heavy one to a light one, you'll never get a good average. Your delivery, to achieve high scores, must be always the same; it must have smoothness and coordination. And, after all, coordination is the thing you must strive for."
Sterling Publishing Co., 1951