Three 19th-century pitchers are known to have thrown with both hands: Tony Mullane in 1882 and again in 1893, Elton Chamberlain in 1888, and Larry Corcoran in 1884.
Greg 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 with his left hand that he felt capable of pitching with either hand in a game.
Harris was not allowed to throw lefty in a regular-season game until September 28, 1995, the next-to-last 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.
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