A rule change that allows voting only for players after 1921 produces four new Hall of Famers: Carl Hubbell, Frank Frisch, Mickey Cochrane, and Lefty Grove, all former M. V.P. s and World Series winners. Hubbell, was forbidden by Ty Cobb to throw his screwball in Detroit’s farm system, but he used it to win 253 games for the Giants. Frisch went to the World Series eight times and batted. 316 over 19 seasons. Grove won 300 games, and his battery mate Cochrane retired with the highest lifetime batting average of any catcher.