Question: has there ever been a switch pitcher in major league baseball

Answer: Yes, Pat Venditte regularly pitches with both arms. Venditte was drafted by the New York Yankees, played for the Seattle Mariners, and now plays for the Philadelphia Phillies. While with the Staten Island Yankees, the Yankees' Single-A affiliate, when he opposed switch hitter Ralph Henriquez, Venditte switched his modified glove to his left arm. (Hitters traditionally derive advantages from batting from the opposite side of the plate to the pitcher's throwing arm.) Henriquez then switched to batting left-handed, and a series of changes continued for several minutes. This prompted the PBUC (Professional Baseball Umpires Corporation) to issue a new rule about switch-pitching. In short, switch-pitchers must indicate to the umpire, batter, and any runners the hand with which they will use to pitch. The pitcher must continue using this hand for the duration of the at bat, with some exceptions for injury and the use of pinch hitters. Following this choice, batters can then select with which hand they will bat.