The strike zone is the area over home plate through which a pitch must pass to be called a strike, roughly between the batter's armpits and knees. The Strike Zone shall be determined from the batter's stance as the batter is prepared to swing at a pitched ball. The strike zone in baseball is a tricky subject as the strike zone changes with each batter. Accordingly, there is no "automatic" strike zone and much of what is a strike or not a strike is left to the judgement of the home plate umpire.