O'Day umpired in ten World Series – second only to Bill Klem's total of 18 – including five of the first seven played, and was behind the plate for the first modern World Series game in 1903. Retiring at age 68 years, 2 months, he remains the oldest umpire in major league history – a fact which was not known until recently, as he routinely shaved five to seven years from his true age throughout his career. His 3,986 total games as an umpire ranked third in major league history when he retired, and his 2,710 games as the plate umpire still rank second in major league history to Klem's total of 3,544. He is largely known for his controversial decision in a pivotal 1908 game, a ruling that still causes debate today. O'Day interrupted his umpiring career twice for single seasons as a manager, leading the Cincinnati Reds in 1912 and the Chicago Cubs in 1914. He remains the only person ever to serve full seasons in the NL as a player, manager and umpire. O'Day was inducted into the National Baseball Hall of Fame in July 2013.