(L-R) Hall of Famers Hank Aaron, Johnny Bench, Sandy Koufax and Willie Mays walk on the field prior to the 86th MLB All-Star Game at Great American Ball Park on July 14, 2015 in Cincinnati, Ohio. During the first half of the season, the four were voted by the fans as the greatest living baseball players. (July 14, 2015 - Source: Elsa/Getty Images North America)