It is at the Little League level of baseball that players actually begin to learn about the strike zone. Before entering Little League, which is for youth 9 to 12 years old, players typically participate in a league in which a machine or coach does the pitching. The definition of the strike zone for Little League Baseball is a modified version of the definition in the Official Baseball Rules that govern Major League Baseball.
In Little League Baseball, as in all levels of play, the strike zone defines the exact area to which the pitcher must deliver the ball for it to be a strike. If the baseball fails to enter the area defined as the strike zone and the batter does not swing at the ball, the umpire should declare the pitch a ball.
The first condition for determining the strike zone for Little League Baseball is the ball must pass over home plate. This condition is not unique to Little League Baseball -- it is a part of the definition of the strike zone at all levels of play. The remaining parts of the definition specify the upper and lower limits of the area above home plate through which the ball must pass.
Upper and Lower Limits
The upper limit of the strike zone for Little League Baseball is the armpit area. This is a modification of the definition in the Official Baseball Rules, which defines the upper limit as midway between the top of the batter’s uniform pants and the top of the shoulders. The lower limit of the Little League Strike zone is the same as defined in the Official Baseball Rules: it is the hollow just below the batter’s kneecaps.
Although the rules clearly define the boundaries of the strike zone, the actual area of the zone varies according to the batter’s stance. The umpire must determine the strike zone based on the batter’s stance when he is ready to swing at the ball. A batter can make the strike zone smaller and more difficult for the pitcher if he bends his knees and hunkers down as he prepares to hit the ball. The strike zone becomes very important at the Little League level as young players begin to learn and practice such techniques.