John Bertrand (Jocko) Conlan, born December 6, 1899 in Chicago, was an outstanding umpire for 24 years in the National League from 1941 to 1964. One July afternoon, during his short stint as a Chicago White Sox outfielder, Jocko volunteered to fill in for an umpire who had been overcome by the blistering heat. The following season he turned in his bat and glove and started his career as an umpire where he went on to umpire in five World Series and six All-Star Games. Jocko was the only umpire of his time to call all of his signals left-handed.
-Michael Rinehart Jr.
Conlan spent some time as the batboy for the White Sox in his youth.