Sometimes, if you’re a pitcher, it seems elusive. If you’re a batter, it can sometimes seem larger than life. The strike zone — in some ways, it is baseball’s version of the Twilight Zone: sometimes it’s hard to tell where it really is.
The strike zone is the area over home plate through which a pitcher must pitch the ball in order for the pitch to be called a strike if the batter does not swing. The idea is that the ball must pass through an area where the batter has a chance to put the ball into play if he swings at it. According to the MLB’s Official Rules:
The STRIKE ZONE is that area over home plate 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 Strike Zone shall be determined from the batter’s stance as the batter is prepared to swing at a pitched ball.
Or, to make things simpler, many regard the area from the elbows to the bottom of the knees as the vertical axis of the strike zone.
The size of the strike zone has not remained static through the years. Major League Baseball will sometimes make the official strike zone larger or smaller in order to maintain a balance of power between pitchers and hitters. For example, after Roger Maris broke Babe Ruth’s home run record in the 1961 season, the strike zone was stretched to extend from the top of the batter’s shoulders to the bottom of the knees. Then, in 1968, pitchers such as Don Drysdale, Bob Gibson, and Denny McLain utterly dominated hitters. As a result, not only was the size of the strike zone reduced in 1969, but the height of the pitchers mound was also reduced from 15 inches to 10 inches tall.
At the end of the day, though, enforcement of the strike zone lies with the home plate umpire. As any player or fan of the game knows, the size — and, sometimes, even the shape — of the strike zone can vary from one umpire to the next. As a result, pitchers and hitters often find themselves having to adjust their expectations according to those of the umpire. And, sometimes, the umpire can be the most loved or the most hated person in the ballpark.