The rarest of baseball players: an ambidextrous pitcher Using a glove with two thumbs, Creighton University pitcher Pat Venditte, shown here in a 2008 game, pitched to right-handed batters with his right hand, then switched to face left-handed batters with his left hand. After one switch-hitter switched sides of the plate, Venditte switched pitching arms, which triggered the batter to switch again, and so on. The umpires ultimately ended the comedy routine by applying a little-known rule: A pitcher must declare which arm he will use before throwing his first pitch to a batter (Schwarz, 2007).