The strike zone in baseball refers to a specific area of space, in which the pitcher must ensure their throw passes through to have the ball called a strike, even if the batter decides not to swing. The strike zone is considered the amount of space from the home plate and between the batter’s knees and midpoint of their torso. The umpire located behind the batter decides whether a ball has passed through the strike zone or not.
If a pitch misses the strike zone when thrown, it is considered a ball if the batter decides not to swing. The strike zone can be used to both the advantage of offense and defense, as strikes are useful for the pitcher, whilst balls are more useful for the batter as it could eventually lead to a walk.