[1] A no-hitter is officially recognized by Major League Baseball only "when a pitcher (or pitchers) allows no hits during the entire course of a game, which consists of at least nine innings", though one or more batters "may reach base via a walk, an error, a hit by pitch, a passed ball or wild pitch on strike three, or catcher's interference".[3] Mike Witt threw the only perfect game, a special subcategory of no-hitter, in Angels history on September 30, 1984.The smallest margin of victory was 1–0 wins by Ryan in 1975, Mike Witt in 1984 and a combined no-hitter led by Langston in 1990."[5] Part of the duties of the umpire making calls at home plate includes defining the strike zone, which "is defined as that area over homeplate (sic) the upper limit of which is a horizontal line at the midpoint between the top of the shoulders and the top of the uniform pants, and the lower level is a line at the hollow beneath the kneecap.The tasks of the manager include determining the starting rotation as well as batting order and defensive lineup every game.