MLB Strike Zone
The official strike zone is the area over home plate from the midpoint between a batter's shoulders and the top of the uniform pants -- when the batter is in his stance and prepared to swing at a pitched ball -- and a point just below the kneecap. In order to get a strike call, part of the ball must cross over part of home plate while in the aforementioned area.
MLB Strike Zone
1957 - "A strike is a legal pitch when so called by the umpire which (a) is struck at by the batter and is missed; (b) enters the Strike Zone in flight and is not struck at; (c) is fouled by the batter when he has less than two strikes at it; (d) is bunted foul; (e) touches the batter as he strikes at it; (f) touches the batter in flight in the Strike Zone; or (g) becomes a foul tip. Note: (f) was added to the former rule and definition."
1907 - "A fairly delivered ball is a ball pitched or thrown to the bat by the pitcher while standing in his position and facing the batsman that passes over any portion of the home base, before touching the ground, not lower than the batsman's knee, nor higher than his shoulder. For every such fairly delivered ball, the umpire shall call one strike."
1894 - "A strike is called when the batter makes a foul hit, other than a foul tip, while attempting a bunt hit that falls or rolls upon foul ground between home base and first or third bases."
In baseball, the strike zone is the volume of space through which a pitch must pass in order to be called a strike even if the batter does not swing. The strike zone is defined as the volume of space above home plate and between the batter's knees and the midpoint of their torso. Whether a pitch passes through the zone is decided by an umpire, who is generally positioned behind the catcher.
Strikes are desirable for the pitcher and the fielding team, as three strikes result in a strikeout of that batter. A pitch that misses the strike zone is called a ball if the batter doesn't swing. Balls are desirable for the batter and the batting team, as four balls allow the batter to take a "walk" to first base as a base on balls.
The strike zone is a volume of space, a vertical right pentagonal prism. Its sides are vertical planes extending up from the edges of home plate. In Major League Baseball, the top of the strike zone is the midpoint between the top of the batter's shoulders and the top of the uniform pants, and the bottom of the strike zone is at the hollow beneath the kneecap, both determined from the batter's stance as the batter is prepared to swing at the pitched ball. Various rulebooks for baseball and softball define the strike zone slightly differently.
Although the de facto enforced strike zone can vary, the Official Rules (Definitions of Terms, STRIKE (b)) define a pitch as a strike "if any part of the ball passes through any part of the strike zone", with the ball required to have not bounced. Thus, a pitch that touches the outer boundary of the zone is as much a strike as a pitch that is thrown right down the center. A pitch passing outside the front of the strike zone but curving so as to enter this volume farther back (without being hit) is called a "back-door strike".
A batter who accumulates three strikes in a single batting appearance has struck out and is ruled out (with the exception of an uncaught third strike); a batter who accumulates four balls in a single appearance has drawn a base on balls (or walk) and is awarded advancement to first base. In very early iterations of the rules during the 19th century, it took up to 9 balls for a batter to earn a walk; however, to make up for this, the batter could request the ball to be pitched high, low, or medium.
Originally, the word "strike" was used literally: the batter striking at the ball in an effort to hit it. For example, the 11th of the Knickerbocker Rules (1845) read "Three balls being struck at and missed and the last one caught, is a hand-out." There was no adverse consequence if the batter chose not to swing, i.e. the called strike did not exist, the result being batters prepared to wait all day for "their" pitch. It was not until the 1858 NABBP convention that a rule was adopted authorizing the umpire to impose a penalty strike for such conduct: "Should a striker stand at the bat without striking at good balls repeatedly pitched to him, for the purpose of delaying the game or of giving advantage to a player, the umpire, after warning him, shall call one strike, and if he persists in such action, two and three strikes. When three strikes are called, he shall be subject to the same rules as if he had struck at three balls." The called ball first appeared in the rules of 1863, similarly as a discretionary penalty imposed on the pitcher for persistently delivering "unfair" balls.
Whether or not a pitch was "unfair," or the batter was being unreasonably picky, was a matter left entirely to the umpire's judgment; well into the 1870s umpires were reluctant to make such calls, since they were viewed as penalties for unsportsmanlike play. But by the 1880s they had become routine, and the modern view according to which every pitch results in either a swing, a ball or a called strike had taken hold. The first rule leading to the creation of a defined strike zone was enacted by the American Association before the 1886 season. As explained in The Sporting Life on March 17, 1886, "the ball must be delivered at the height called for by the batsman. If at such height it passes over any part of the plate then it is a strike. The idea is to give the pitcher a chance against some cranky umpires who compelled the twirlers to almost cut the plate in two before a strike would be called, even if the height was right." The following year, the National League created the full strike zone, eliminating the batter's right to call the height of the pitch, and instead requiring the umpire to call a strike on any pitch that "passes over home plate not lower than the batsman's knee, nor higher than his shoulders."
Major League Baseball has occasionally increased or reduced the size of the strike zone in an attempt to control the balance of power between pitchers and hitters. After the record home run year by Roger Maris in 1961, the major leagues increased the size of the strike zone from the top of the batter's shoulders to the bottom of his knees. In 1968, pitchers such as Denny McLain and Bob Gibson among others dominated hitters, producing 339 shutouts. Carl Yastrzemski would be the only American League hitter to finish the season with a batting average higher than .300. In the National League, Gibson posted a 1.12 earned run average, the lowest in 54 years, while Los Angeles Dodgers pitcher Don Drysdale threw a record 58 and two-thirds consecutive scoreless innings during the 1968 season. As a result of the dropping offensive statistics, Major League Baseball took steps to reduce the advantage held by pitchers by lowering the height of the pitcher's mound from 15 inches to 10 inches, and by reducing the size of the strike zone for the 1969 season.
The Official Baseball Rules (Rule 8.02(a), including Comment) state that objections to judgment calls on the field, including balls and strikes, shall not be tolerated, and that any manager, coach, or player who leaves his dugout or field position to contest a judgment call will first be warned, and then ejected.
As of 2022, Minor league baseball had used Automated Balls and Strikes on an experimental basis for several seasons. While the umpire continued to call balls and strikes, an automated system determined the strike zone and could be used when a team challenged the umpire's call. Major League Baseball commissioner Rob Manfred said in October 2022 that this method would eventually be used in Major League games. ESPN reported that all AAA games would use the method in the 2023 season.
As shown by Mills, the strike zone has evolved since 2007, the year when Major League Baseball began using Pitch f/x technology to monitor the speed, movement, and location of pitches. The actual strike zone has become a little more narrow and umpires are more likely to call strikes lower in the zone.
The STRIKE ZONE is excited to announce we will be REOPENING at new locations around The North Shore and offering clinics in December and into the new year. Also, feel free to contact Jack French at email@example.com to continue your baseball training and learn more about what is to come in the future.
Olney notes the Automated Balls and Strikes system, commonly referred to as ABS, will be used in two different ways, with 15 of the Class AAA stadiums using all of the calls determined by an electronic strike zone, and the other half will be played with an ABS challenge system similar to that used in professional tennis.
In 2019, the independent Atlantic League used the electronic strike zone in an all-star game, and that same year, the Arizona Fall League was played with the ABS. In 2021, the ABS was deployed in some Class A parks. Last season, the full ABS was used for some Class AAA games.
In the example below, you can see two views of the exact same pitch. From the mound view the pitch looks to be a ball, but a closeup shows it was a strike just barely on the edge of the zone. For a pitch this close to the strike zone, the accuracy tolerance of a machine calling balls and strikes is critical.
Additionally, the rule book strike zone is somewhat subjective as well and would likely need a further refined definition if machine systems were to be implemented for calling strikes in a live game. Dr. David Kagan recently explored this aspect of the robo zone problem, noting that it remains one of the largest obstacles to implementation.
If there were a Robo Zone, at some point there would need to be agreement on how to interpret the rule book strike zone using machine data. Dr. Kagan pointed out that MLB is using previous umpire calls to set the zone rather than stringers now: 041b061a72