Greg A. Harris is the only major league pitcher in the modern era to pitch with both his left and his right arm. A natural righty, by 1986 he could throw well enough left-handed that he felt capable of pitching with either arm in a game. Harris did not throw lefty in a regular-season game until September 28, 1995, the penultimate game of his career. Against the Cincinnati Reds in the ninth inning, Harris (then a member of the Montreal Expos) retired Reggie Sanders pitching right-handed, then switched to his left hand for the next two hitters, Hal Morris and Ed Taubensee, who both batted left-handed. Harris walked Morris but got Taubensee to ground out. He then went back to his right hand to retire Bret Boone to end the inning.
Pat Venditte, who played college baseball for the Creighton Bluejays, regularly pitches with both arms. Venditte was drafted by the New York Yankees, and now plays for the Scranton/Wilkes-Barre RailRiders, the Yankees' AAA 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 rules about switch-pitching: switch-pitchers must choose which way they will begin pitching before they start. Then, batters will select with which hand they will bat. The batter and the pitcher are each allowed one switch during the plate appearance, after the first pitch is thrown.
In the collegiate ranks, Matt Brunnig (Harvard class of 2006-07) was able to pitch over 85 mph left-handed and over 90 mph right-handed, but only pitched with both arms in the same game a few times. In college he pitched more from the right side as a starter and pitched some relief as a lefty although he did start one game left-handed. When playing the outfield after a start he would typically play the position with the other arm to rest the arm he just pitched with.
Switch-throwers are commonly taught to switch-throw at a young age. For instance, Venditte's father trained him in ambidextrous throwing from the age of three and Brunnig's father (a chiropractor) taught him from age five.
- George Wheeler's page at Baseball Reference
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- The Associated Press. "Ambidextrous pitcher stars at Creighton". MSNBC, May 3, 2006. Accessed 12 June 2007.
- German, Norman. Switch-Pitchers. St. Augustine, Florida: BluewaterPress LLC, 2010. In this novel Ernest Hemingway smuggles twin Cuban pitchers to the U.S. for a shot at major league fame. A dugout full of rats reveals one to be a switch-pitcher when he throws at the rats equally well either right- or left-handed.
- Holtzman, Jerome. "A lesson in switch-pitching". MajorLeagueBaseball.com via the Internet Archive, March 3, 2000. Accessed 12 June 2007.