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{{short description|Target zone for a pitched baseball}}
{{Redirect|Ball (baseball)|the object|Baseball (ball)|other uses|Strike zone (disambiguation)}}
[[File:Strike zone en.JPG|thumb|A labelled drawing of the strike zone superimposed onto an image from a game, showing a [[Baseball rules#Batting team|batter]], [[catcher]] and [[Umpire (baseball)|umpire]]. The [[pitcher]] (not pictured) pitches a baseball to the catcher; the batter attempts to hit this baseball; and the umpire decides whether pitches are balls or strikes.]]

In [[baseball]], the '''strike zone '''is the area of space through which a [[Pitch (baseball)|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 [[Baseball field#Home base|home plate]] and between the batter's knees and the midpoint of his [[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 [[Baseball rules#Fielding team|fielding team]], as three strikes result in a [[strikeout]] of that batter. A pitch that misses the strike zone is called a [[Baseball rules#Batting|ball]] if the batter does not swing at it. Balls are desirable for the [[Batting (baseball)|batter]] and the [[Baseball rules#Batting team|batting team]], as four balls allow the batter to take a "walk" to first base as a [[base on balls]].

[[File:Umpire catcher strike zone - Tokyo - 2024 April 21.webm|thumb|[[Tetsuto Yamada]] of the [[Tokyo Yakult Swallows]] swings and misses for strike one, 2024]]

==Definition==
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]]. The official rules of [[Major League Baseball]] define the top of the strike zone as the midpoint between the top of the batter's [[shoulder]]s and the top of his uniform pants, and the bottom of the strike zone is at the hollow beneath the [[kneecap]], both determined from the batter's stance as he is prepared to swing at the pitched ball, although the ''[[de facto]]'' enforced strike zone can vary based on the umpire's perspective. The official rules 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 [[In flight|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 sometimes called a "back-door strike". Various other rulebooks for baseball and [[softball]] define the strike zone slightly differently. 

A pitch is also a strike if the batter swings or offers the bat in an attempt to hit the pitch. A pitch batted into foul territory—a [[foul ball]]—is also a strike, unless the batter already has two strikes. Any pitch not called a strike, swung on and missed, or fouled-off, is a "ball" (originally "no ball"). 

A batter who accumulates three strikes in a single batting appearance has [[Strikeout|struck out]] and is ruled [[Out (baseball)|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 nine balls for a batter to earn a walk. However, to make up for this, he could request the ball to be pitched high, low, or medium.<ref>{{cite news |title=What An MLB Strike Zone Really Looks Like And Why Players Are Always So Mad About It |url=http://www.businessinsider.com/mlb-strike-zone-2014-9 |work=Business Insider |access-date=2018-04-29}}</ref>

==History==
Originally, the word "strike" was used literally: the batter ''striking'' at the ball in an effort to hit it. For example, the 11th rule 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 did not 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 [[National Association of Base Ball Players|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."<ref>{{cite web |title=1858 NABBP Rules – Protoball |url=https://protoball.org/1858_NABBP_Rules}}</ref> The called ball first appeared in the rules of 1863, similarly as a discretionary penalty imposed on the pitcher for persistently delivering "unfair" balls.<ref>"Should the pitcher repeatedly fail to deliver to the striker fair balls, for the apparent purpose of delaying the game, or for any other cause, the umpire, after warning him, shall call one ball, and if the pitcher persists in such action, two and three balls; when three balls shall have been called, the striker shall be entitled to the first base; and should any base be occupied at that time, each player occupying them shall be entitled to one base without being put out." https://protoball.org/1863_NABBP_Rules</ref>

Whether or not a pitch was "unfair" or the batter was being unreasonably picky was left entirely to the umpire's judgment. Well into the 1870s, umpires were reluctant to make such calls,<ref>"In [calling balls] on pitchers, the rule to be observed this season by leading umpires will be as follows: When the game commences, the umpire, after making such allowance for accidental unfair delivery as the circumstances will justify, will without appeal call “ball to the bat,” after which notice should the pitcher fail “repeatedly”, viz., twice or three times to deliver a fair ball, then the umpire will call “one ball;” and if the pitcher persists in such action, that is, delivers one or two unfair balls directly after such warning and calling of one ball, two and three balls are to be called, and the player given his base. Less latitude will be allowed in this matter than was permitted last season, and the practice of taking the opinion of the two nines or their captains as to the degree of latitude to be observed in making allowance for unfair balls is to be entirely done away with." ''New York Clipper'', March 25, 1865</ref> since they were viewed as penalties for unsportsmanlike play. By the 1880s, they had become routine, and the modern view took hold, that every pitch results in either a swing, a ball or a called strike. The first rule leading to the creation of a defined strike ''zone'' was enacted by the [[American Association (19th century)|American Association]] before the 1886 season. As explained in ''[[Sporting Life (American newspaper)|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 [[Home plate|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."<ref>"A Definition", in ''The Sporting Life'', Wednesday, March 17, 1886, p. 1, col. 2.</ref> The following year, the [[National League (baseball)|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."<ref>{{cite web |title=The Strike Zone: A History of Official Strike Zone Rules by Baseball Almanac |url=https://www.baseball-almanac.com/articles/strike_zone_rules_history.shtml}}</ref>

Major League Baseball has occasionally redefined the strike zone to control the balance of power between pitchers and hitters.<ref name="1968: Year of the Pitcher">{{cite web |url=http://www.thisgreatgame.com/1968.html |title=1968: Year of the Pitcher |publisher=thisgreatgame.com |access-date=25 December 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111224181907/http://www.thisgreatgame.com/1968.html |archive-date=24 December 2011}}</ref> After the record home run year by [[Roger Maris]] in {{Baseball year|1961}}, the major leagues increased the size of the strike zone by raising the top of the zone from the batter's armpit to the top of his shoulder.<ref name="mlb_strike_zone">{{Cite web|title=Strike Zone|website=[[MLB.com]] |url=https://www.mlb.com/glossary/rules/strike-zone|date=January 20, 2024}}</ref><ref>{{cite news |title=Expanded strike zone unveiled |agency=Associated Press |work=The Press-Courier |page=9 |date=8 March 1963 |access-date=25 December 2011 |url=https://news.google.com/newspapers?id=AxpLAAAAIBAJ&sjid=4SINAAAAIBAJ&pg=7088,849307&dq=1962+strike+zone&hl=en}}</ref> In {{Baseball year|1968}}, pitchers such as [[Denny McLain]] and [[Bob Gibson]] dominated hitters, producing 339 [[shutout]]s.<ref name="1968: Year of the Pitcher"/> [[Carl Yastrzemski]] was the only [[American League]] hitter to finish the season with a [[batting average (baseball)|batting average]] higher than .300.<ref name="1968: Year of the Pitcher"/> In the [[National League (baseball)|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 {{frac|58|2|3}} consecutive scoreless innings during the 1968 season.<ref name="1968: Year of the Pitcher"/> As a result of the dropping offensive statistics, Major League Baseball reduced pitchers' advantage by lowering the height of the mound from {{convert|15|in}} to {{convert|10|in}}, and by reducing the size of the strike zone for the {{Baseball year|1969}} season to extend only from the batter's armpits to the top of the knees.<ref name="mlb_strike_zone" /><ref>{{cite news |title=McLain Says Lower Mound Will Take Toll of Pitchers |agency=Associated Press |work=The Telegraph-Herald |page=13 |date=14 January 1969 |access-date=25 December 2011 |url=https://news.google.com/newspapers?id=LWNFAAAAIBAJ&sjid=KbwMAAAAIBAJ&pg=5404,1728619&dq=denny+mclain+pitching+mound&hl=en}}</ref> In 1985, the top of the strike zone was lowered to the midpoint of the batter's torso, as viewed from a vertical angle by the umpire.<ref name=mlb_strike_zone/>

==Enforcement==
[[File:Barry Bonds strike.jpg|thumb|An umpire calling a strike on [[Barry Bonds]] (#25)]]

While baseball rules provide a precise definition for the strike zone, in practice, it is up to the judgment of the [[Umpire (baseball)|umpire]] to decide whether the pitch passed through the zone.

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 any manager, coach, or player who leaves his dugout or field position to contest a judgment call will first be warned, and then ejected.<ref>{{Cite web|url=http://mlb.mlb.com/documents/0/8/0/268272080/2018_Official_Baseball_Rules.pdf|title=Official Baseball Rules, 2018|publisher=Major League Baseball|access-date=2018-06-20}}</ref>

Many umpires, players and analysts, including the authors of a University of Nebraska study on the subject,<ref>[http://www.newswise.com/articles/view/528743/ Newswise Social and Behavioral Sciences News | Larger Strike Zone, Drug Testing Reduced Hitting in Baseball Since 2000<!-- Bot generated title -->]</ref> believe that due to the [[QuesTec]] pitch-tracking system, the enforced strike zone in 2002–2006 was larger compared to the zone in 1996–2000 and thus closer to the rulebook definition. Some commentators believed the zone had changed so much that some pitchers, such as [[Tom Glavine]], had to radically adjust their approach to pitching for strikes.<ref>[http://www.covers.com/articles/articles.aspx?theArt=135777&t=0 Umpires and totals: Men behind the mask occasionally steal the show]</ref> In 2003, a frustrated [[Curt Schilling]] took a baseball bat to a QuesTec camera and destroyed it after a loss, saying the umpires should not be changing the strike zone to match the machines.<ref>[https://web.archive.org/web/20030804043833/http://sportsillustrated.cnn.com/baseball/news/2003/06/02/schilling_fined_ap/ D'backs' Schilling fined for destroying QuesTec camera]</ref>

In 2009, a new system called Zone Evaluation was implemented in all 30 Major League ballparks, replacing the QuesTec system; the new system records the ball's position in flight more than 20 times before it reaches home plate.<ref>[https://www.nytimes.com/2009/04/01/sports/baseball/01umpires.html?_r=3&ref=sports|Ball-Strike Monitor May Reopen Wounds], an April 2009 article from ''[[The New York Times]]''</ref> Much of the early resistance from Major League umpires to QuesTec had diminished and the implementation of the new Zone Evaluation system in all the parks went largely unmentioned to fans. Like the old system, the new system will be used to grade umpires on accuracy and used to determine which umpires receive postseason assignments, but games themselves are still subject to their error.<ref>[http://www.startribune.com/sports/twins/42435022.html?page=2&c=y|Baseball Preview 2009: The umpires' arbiter] from an April 2009 ''[[Star Tribune]]'' article</ref>

As of 2022, [[Minor League Baseball]] has been testing the [[Automated Ball-Strike System]] (ABS) on an experimental basis for several seasons. While the umpire continues to call balls and strikes, ABS determines 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 ABS would eventually be used in Major League games. ESPN reported that all [[Triple-A (baseball)|AAA]] games would use ABS in the 2023 season.<ref>{{cite news|url=https://www.usatoday.com/story/sports/ftw/2022/10/10/mlb-rob-manfred-automatic-strike-zone/10462411002/|title=Rob Manfred confirms automated strike zone is coming to MLB 'in one form or another'|last=Joseph|first=Andrew|work=[[USA Today]]|date=2022-10-10|access-date=2023-01-14}}</ref><ref>{{cite news|url=https://www.charlotteobserver.com/sports/mlb/charlotte-knights/article271146907.html|title=It worked for Charlotte Knights. Now electronic strike zone will be in all AAA baseball|last=Zietlow|first=Alex|work=[[The Charlotte Observer]]|date=2023-01-13}}</ref> For 2023, the system was used for half of all games, with the other half using umpires, with ABS used for up to three challenges per team for each game.<ref>{{cite news|url=https://www.charlotteobserver.com/sports/article276608021.html|title=Automated umpire system earns high marks from Charlotte Knights|last=Effress|first=Sarah|work=The Charlotte Observer|date=2023-07-01}}</ref>

==See also==
{{Portal|Baseball}}
*[[Glossary of baseball terms]]

==References==
{{Reflist}}

==Further reading==
*{{cite magazine |last=Gammons |first=Peter |author-link=Peter Gammons |date=April 6, 1987 |title=What Ever Happened to the Strike Zone? |magazine=Sports Illustrated |volume=66 |issue=14 |pages=36–40, 45–46 }}

==External links==
*[http://www.sptimes.com/News/022701/Sports/Baseball_adapts_to_a_.shtml 2001 Changes in Strike Zone] ''[[St. Petersburg Times]]'' article.
*[http://mlb.mlb.com/NASApp/mlb/mlb/official_info/umpires/rules_interest.jsp Strike Zone] MLB website.
*John Walsh, [http://www.hardballtimes.com/main/article/strike-zone-fact-vs-fiction "Strike Zone: Fact vs. Fiction"], ''[[The Hardball Times]]'', July 11, 2007
*[http://www.baseball-almanac.com/articles/strike_zone_rules_history.shtml The Strike Zone: A Chronological Examination of the Official Rules] baseball-almanac

{{Baseball|state=expanded}}
{{Baseball pitches}}

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[[Category:Batting (baseball)]]
[[Category:Pitching (baseball)]]
[[Category:Baseball terminology]]
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