At 1948’s spring training in Dodgertown, Rickey implemented novel training methods such as strings to help his pitchers visualize the strike zone (left), and batting cages and pitching machines (right). Photos by George Silk for Life magazine, 5 April 1948, and reproduced at Ben Cosgrove, “LIFE with Dem Bums: Spring Training at Dodgertown, 1948,” Time.com, 28 February 2013