 Pat Venditte played for the Oakland A's in 2015 and actually spent some time with the Mariners the next year. In 2008, the Pro Baseball Umpires Corporation created the Venditte Rule. An ambidextrous pitcher must visually indicate to the umpire, batter, and any base runners the hand with which he intends to pitch. And he can't change hands until that batter's out or on base.