A shot clock is a countdown timer used in a variety of games and sports, indicating a set amount of time that a team may possess the object of play before attempting to score a goal. Shot clocks are used in several sports including
basketball
Basketball is a team sport in which two teams, most commonly of five players each, opposing one another on a rectangular Basketball court, court, compete with the primary objective of #Shooting, shooting a basketball (ball), basketball (appro ...
,
water polo
Water polo is a competitive sport, competitive team sport played in water between two teams of seven players each. The game consists of four quarters in which the teams attempt to score goals by throwing the water polo ball, ball into the oppo ...
,
canoe polo
Canoe polo, also known as kayak polo or polo (to players and fans), is one of the competitive disciplines of kayaking. It incorporates ball-handling skills into a contact team game, wherein group tactics and positional play are as important as in ...
,
lacrosse
Lacrosse is a contact team sport played with a lacrosse stick and a lacrosse ball. It is the oldest organized sport in North America, with its origins with the indigenous people of North America as early as the 12th century. The game w ...
,
poker
Poker is a family of Card game#Comparing games, comparing card games in which Card player, players betting (poker), wager over which poker hand, hand is best according to that specific game's rules. It is played worldwide, with varying rules i ...
,
ringette
Ringette is a winter team sport played on an ice rink using ice hockey skates, straight sticks with drag-tips, and a blue, rubber, pneumatic ring designed for use on ice surfaces. While the sport was originally created exclusively for female c ...
,
korfball
Korfball ( ) is a ball sport, with similarities to netball, basketball, and ringball. The objective is to throw a ball into a netless basket that is mounted on a pole. Each team is composed of four female players and four male players. The s ...
,
tennis
Tennis is a List of racket sports, racket sport that is played either individually against a single opponent (singles (tennis), singles) or between two teams of two players each (doubles (tennis), doubles). Each player uses a tennis racket st ...
,
ten-pin bowling
Tenpin bowling is a type of bowling in which a bowler bowling form, rolls a bowling ball down a wood or synthetic lane toward ten pins positioned Tetractys, evenly in four rows in an equilateral triangle. The goal is to knock down all ten Bowlin ...
, and various
cue sports
Cue sports are a wide variety of Game of skill, games of skill played with a cue stick, which is used to strike billiard balls and thereby cause them to move around a Baize, cloth-covered billiards table, table bounded by elastic bumpers known a ...
. It is analogous with the
play clock used in
American and
Canadian football
Canadian football, or simply football, is a Sports in Canada, sport in Canada in which two teams of 12 players each compete on a field long and wide, attempting to advance a Ball (gridiron football), pointed oval-shaped ball into the opposi ...
, and the
pitch clock
A pitch clock (also known as a pitch timer) is used in various baseball leagues to limit the amount of time a pitcher takes before throwing the ball to the Batting (baseball), hitter and/or limit the amount of time the hitter uses before he is s ...
used in
baseball
Baseball is a bat-and-ball games, bat-and-ball sport played between two team sport, teams of nine players each, taking turns batting (baseball), batting and Fielding (baseball), fielding. The game occurs over the course of several Pitch ...
. This article deals chiefly with the shot clock used in basketball.
The set amount of time for a shot clock in basketball is 24–35 seconds, depending on the league. This clock reveals how much time a team may possess the ball before attempting to score a
field goal. It may be colloquially known as the 24-second clock, particularly in the
NBA
The National Basketball Association (NBA) is a professional basketball league in North America composed of 30 teams (29 in the United States and 1 in Canada). The NBA is one of the major professional sports leagues in the United States and Ca ...
and other leagues where that is the duration of the shot clock. If the shot clock reaches zero before the team attempts a field goal, the team has committed a shot clock violation, which is penalized with a loss of possession.
At most professional and collegiate basketball courts the shot clock is displayed to the players and spectators in large red numerals below the game clock on a display mounted atop each backboard. In some collegiate and amateur facilities this display might be located on the floor or mounted to a wall behind the end line. A shot clock is used in conjunction with a game clock but is distinct from the game clock which displays the time remaining in the period of play.
The shot clock was originally introduced in the NBA in 1954 as a way to increase scoring and reduce stalling tactics that were commonly used before its inception. It has been credited with increasing fan interest in the then-fledgling league, and has since been adopted at most organized levels of basketball.
Definition
The shot clock is a
digital clock that displays a number of seconds or not. The shot clock is usually displayed above the backboard behind each goal, allowing offensive players to see precisely how much time they have to shoot and officials to easily determine whether
buzzer beater
In timed sports, a buzzer beater is a successful shot made as the clock expires at the end of a period or at the end of the game, leaving zero seconds remaining. A buzzer sounds whenever a game clock expires, hence the name "buzzer beater." In b ...
s should be counted. The NBA specifies that a transparent shot clock and game clock that displays said times on both sides be part of the backboard assembly, and FIBA, EuroLeague, and many venues use this arrangement.
Three signals indicate when the time to shoot has expired:
*A value of 0.0 on the shot clock itself
*An audible horn distinct from the scoreboard operator's signal for end of period and substitutions
*A yellow strip of lights (
LED
A light-emitting diode (LED) is a semiconductor device that emits light when current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy in the form of photons. The color of the light (corresp ...
s) on the backboard. The NBA (since 2011) and FIBA (since July 2018) require this. This is not explicitly required in the NCAA, although some venues will use the red LEDs surrounding most shot clocks or on the backboard (used in the NBA to signal the end of period) to denote a shot clock violation.
In the final five seconds to shoot, the shot clock displays tenths of seconds. This was adopted in the
2011–12 NBA season
The 2011–12 NBA season was the 66th season of the National Basketball Association (NBA). Due to the 2011 NBA lockout, lockout, the regular season was reduced to 66 games for each team, and began on December 25, 2011, coinciding with NBA Christm ...
.
History
The NBA has had a 24-second limit since 1954.
FIBA
The International Basketball Federation (FIBA ; French language, French: ) is an association of national organizations which governs the sport of basketball worldwide. FIBA defines the rules of basketball, specifies the Basketball equipment ...
introduced a 30-second shot clock in 1956 and switched to 24 seconds in 2000. The
Women's National Basketball Association
The Women's National Basketball Association (WNBA) is a women's professional basketball league in the United States. The league comprises 13 teams (scheduled to expand to 15 in 2026). The WNBA is headquartered in Midtown Manhattan.
The WNBA w ...
(WNBA) had a 30-second clock originally and switched to 24 seconds in 2006. Collegiate basketball uses a 30-second shot clock (details
below
Below may refer to:
*Earth
*Ground (disambiguation)
*Soil
*Floor
* Bottom (disambiguation)
*Less than
*Temperatures below freezing
*Hell or underworld
People with the surname
* Ernst von Below (1863–1955), German World War I general
* Fred Belo ...
).
Background

The NBA had problems attracting fans (and positive media coverage) before the shot clock's inception.
Teams in the lead were
running out the clock
In sports strategy, running out the clock, also known as running down the clock, stonewalling, killing the clock, chewing the clock, stalling, eating clock or time-wasting (or timewasting), is the practice of a winning team allowing the clock to e ...
, passing the ball incessantly. The trailing team could do nothing but commit fouls to recover possession following the free throw. Frequent low-scoring games with many fouls bored fans. The most extreme case occurred on November 22, 1950, when the
Fort Wayne Pistons defeated the
Minneapolis Lakers
The Los Angeles Lakers franchise has a long and storied history, having played and won championships in both the National Basketball League (United States), National Basketball League (NBL) and the Basketball Association of America (BAA) prior to ...
by a record-low score of 19–18, including 3–1 in the fourth quarter.
["History of the Shot Clock"](_blank)
NBA. The Pistons held the ball for minutes at a time without shooting (they attempted 13 shots for the game) to limit the impact of the Lakers' dominant
George Mikan
George Lawrence Mikan Jr. (; June 18, 1924 – June 1, 2005), nicknamed "Mr. Basketball", was an American professional basketball player for the Chicago American Gears of the National Basketball League (NBL) and the Minneapolis Lakers of ...
. It led the ''
St. Paul Dispatch'' to write, "
he Pistonsgave pro basketball a great black eye."
NBA President
Maurice Podoloff
Maurice Podoloff (; August 18, 1890 – November 24, 1985) was an American lawyer and a basketball and ice hockey administrator. He served as the president of the Basketball Association of America (BAA) from 1946 to 1949, and the National Basketb ...
said, "In our game, with the number of stars we have, we of necessity run up big scores."
A few weeks after the Pistons/Lakers game, the
Rochester Royals
The Sacramento Kings are an American professional basketball team based in Sacramento, California. The Kings compete in the National Basketball Association (NBA) as a member of the Pacific Division (NBA), Pacific Division of the Western Confere ...
and
Indianapolis Olympians played a six-overtime game with only one shot in each overtime: in each overtime period, the team that had the ball first held it for the entirety of the period before attempting a last-second shot. The NBA tried several rule changes in the early 1950s to speed up the game and reduce fouls before eventually adopting the shot clock.
Creation
In 1954 in
Syracuse, New York
Syracuse ( ) is a City (New York), city in and the county seat of Onondaga County, New York, United States. With a population of 148,620 and a Syracuse metropolitan area, metropolitan area of 662,057, it is the fifth-most populated city and 13 ...
,
Syracuse Nationals
The Philadelphia 76ers are an American basketball team currently playing in the Atlantic Division (NBA), Atlantic Division of the Eastern Conference (NBA), Eastern Conference in the National Basketball Association (NBA). The 76ers are third in NBA ...
(now the Philadelphia 76ers) owner
Danny Biasone and general manager
Leo Ferris
Leo F. Ferris (May 31, 1917 – June 1, 1993) was an American sports executive and businessman from Elmira, New York. He played a critical role in the birth of the National Basketball Association.
Ferris founded the National Basketball League's ...
experimented with a 24-second shot clock during a scrimmage. Jack Andrews, longtime basketball writer for ''The Syracuse Post-Standard'', often recalled how Ferris would sit at Danny Biasone's Eastwood bowling alley, scribbling potential shot clock formulas onto a napkin. According to Biasone, "I looked at the box scores from the games I enjoyed, games where they didn't screw around and stall. I noticed each team took about 60 shots. That meant 120 shots per game. So I took 2,880 seconds (48 minutes) and divided that by 120 shots. The result was 24 seconds per shot."
Ferris was singled out by business manager Bob Sexton at the 1954 team banquet for pushing the shot clock rule. Biasone and Ferris then convinced the NBA to adopt it for the
1954–55 season, a season in which the Nationals won the
NBA Championship
The NBA Finals is the annual championship series of the National Basketball Association (NBA). The Eastern Conference (NBA), Eastern and Western Conference (NBA), Western Conference champions play a best-of-seven series to determine the league ...
Models
Originally, the shot clocks used in the NBA were usually single-sided in a black box. A 1991 rule change required game clocks to be included with shot clocks in the NBA. Eventually, after the rule change, multiple-sided began to be used, and would be in most of the arenas. A 2002 NBA rule change allowing instant replay review of last-second shots required four-sided units in NBA venues, along with an accompanying shot clock light to determine if the shot went off in time. In 2005, the
FedExForum in Memphis opened with a new two-sided transparent shot clock developed by
Daktronics
Daktronics, Inc. is an American company based in Brookings, South Dakota, that designs, manufactures, sells, and services video displays, scoreboards, digital billboards, dynamic message signs, sound systems, and related products. It was found ...
with a smaller secondary version also accompanying the larger one. By the 2010's, the twin shot clock format, used by Daktronics and Canadian rival OES, became the standard for most venues, especially in NCAA play. In the
2014-15 season, the NBA signed a deal with Tissot, a Swiss watch company, for specification two-sided transparent shot clock, which was thinner than its predecessors. But in many international leagues and the collegiate level, the older 3-sided and 4-sided shot clocks are still in use, except for Daktronics, OES, and SwissTiming/Tissot venues.
Adoption by other leagues
Two later pro leagues that rivaled the NBA adopted a modified version of the shot clock. The
American Basketball League used a 30-second shot clock for its two years in existence The
American Basketball Association
The American Basketball Association (ABA) was a major professional basketball league that operated for nine seasons from 1967 to 1976. The upstart ABA operated in direct competition with the more established National Basketball Association thr ...
also adopted a 30-second clock when it launched in switching to the NBA's 24-second length for its final season
From its inception in
1975
It was also declared the ''International Women's Year'' by the United Nations and the European Architectural Heritage Year by the Council of Europe.
Events
January
* January 1 – Watergate scandal (United States): John N. Mitchell, H. R. ...
, the
Philippine Basketball Association
The Philippine Basketball Association (PBA) is a men's professional basketball league in the Philippines, composed of twelve company-branded Franchising, franchise teams. Founded in 1975, it is the first professional basketball league in Asia ...
adopted a 25-second shot clock. This was because the shot clocks then installed at the league's main venues, the
Araneta Coliseum
The Araneta Coliseum, also currently known by naming rights sponsorship as Smart Araneta Coliseum, is an indoor multi-purpose arena, sports arena that is part of the Araneta City in the Quezon City#Cubao, Cubao area of Quezon City, Philippines. ...
and
Rizal Memorial Coliseum
The Rizal Memorial Coliseum is an indoor arena in the Rizal Memorial Sports Complex in Manila, Philippines. It can hold up to 6,100 people.
History
The Rizal Memorial Coliseum within the Rizal Memorial Sports Complex was built on the former si ...
(the latter no longer used by the league), could only be set at 5-second intervals. The league later adopted a 24-second clock starting from the
1995 season. The
Metropolitan Basketball Association
The Metropolitan Basketball Association (MBA), also shortened as Metroball, was a professional basketball league in the Philippines that ran for five seasons from 1998 until 2002.
The MBA was established to rival the Philippine Basketball Asso ...
in the Philippines used the 23-second clock from its maiden season in 1998. In Philippine college basketball, the
NCAA Basketball Championship (Philippines) and the
UAAP Basketball Championship adopted a 30-second clock, then switched to 24 seconds starting with the 2001–02 UAAP season 64, the first season to start after the FIBA rule change in 2001.
Operation
The shot clock begins counting down when a team establishes possession, and stops any time the game clock stops (e.g.,
timeouts, violations, fouls). The offensive team must attempt to score a field goal before the shot clock expires; otherwise, the team has committed a shot clock violation (also known as a 24-second violation in leagues with a 24-second shot clock) that results in a
turnover to their opponents. An important distinction is that there is no violation if the ball is in flight to the basket when the shot clock expires, as long as the ball leaves the player's hand before the shot clock expires and the ball proceeds to go into the basket or touch the basket rim.
The shot clock resets to its full length at the start of each period and whenever possession changes to the opposite team such as after a basket is scored, the defense
steals the ball or recovers a
rebound, or the offense commits a
foul or
violation. The full length varies by country, level of play, and league; see the table
below
Below may refer to:
*Earth
*Ground (disambiguation)
*Soil
*Floor
* Bottom (disambiguation)
*Less than
*Temperatures below freezing
*Hell or underworld
People with the surname
* Ernst von Below (1863–1955), German World War I general
* Fred Belo ...
. The shot clock does not reset if a defender makes short contact with the ball (e.g., an attempted steal or a tipped pass) but the offense retains possession, or if a shot attempt misses the rim entirely and
airballs. The shot clock also resets when the offense retains possession after a missed field goal or free throw, or on certain fouls or violations that give the offense an inbounds pass in their frontcourt.
If the offensive team is fouled and the penalty does not include free throws but just an in-bounds pass, the shot clock is reset. There are several cases where the offense is not given a full 24 seconds. The shot clock is instead set to 14 following an offensive rebound.
FIBA adopted this in 2014 and the NBA adopted in 2018. The WNBA also observes this rule. In several other cases where the offense inbounds the ball in its frontcourt (such as a foul by the defense not resulting in free throws), the offense is guaranteed 14 seconds.
The shot clock is increased to 14 if it showed a shorter time.
On a held ball (whether decided by a
jump ball or a
possession arrow), the state of the shot clock depends on which team gets possession of the ball.
*If the defensive team acquires possession, the shot clock is reset, as it is on any other change of possession.
*If the offense retains possession, the shot clock is not reset, because there was no change of possession. However, in Euroleague, the NBA, and WNBA, the shot clock is topped up to 14 seconds, as described above for a frontcourt inbounds pass.
Near the end of each period, if the shot clock would ordinarily display more time than there is remaining in the period, the shot clock is switched off. During this time, a team cannot commit a shot clock violation.
The shot clock apparatus itself is considered out of bounds and not part of the
backboard. The shot clock operator sits at the scorer's table. This is usually a different person from the scoreboard operator, as the task requires concentration during and after the shot attempt. In the
2016-17 NBA season, a new 'official timekeeper' deal for the NBA with Swiss watch manufacturer
Tissot
Tissot SA () is a Swiss luxury watch brand owned by the Swatch Group. The company was founded in Le Locle, Switzerland by Charles-Félicien Tissot and his son, Charles-Émile Tissot, in 1853.
Tissot is not associated with Mathey-Tissot, anoth ...
introduced technology to unify the keeping of the shot clock and the game clock. Tissot also became official timekeeper for the WNBA in the 2017 season.
Collegiate rules
American collegiate basketball uses a 30-second shot clock, while Canadian university basketball uses a 24-second clock.
In men's collegiate basketball, there was initial resistance to the implementation of a shot clock for men's
NCAA
The National Collegiate Athletic Association (NCAA) is a nonprofit organization that regulates College athletics in the United States, student athletics among about 1,100 schools in the United States, and Simon Fraser University, 1 in Canada. ...
basketball, due to fears that smaller colleges would be unable to compete with powerhouses in a running game. However, after extreme results like an 11–6
Tennessee
Tennessee (, ), officially the State of Tennessee, is a landlocked U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders Kentucky to the north, Virginia to the northeast, North Carolina t ...
win over
Temple
A temple (from the Latin ) is a place of worship, a building used for spiritual rituals and activities such as prayer and sacrifice. By convention, the specially built places of worship of some religions are commonly called "temples" in Engli ...
in 1973, support for a men's shot clock began to build.
The NCAA introduced a 45-second shot clock for the
1985-86 season;
several conferences had experimented with it for the two seasons prior.
It was reduced in the
1993–94 season, and in the
2015–16 season. The
NAIA also reduced the shot clock to 30 seconds starting in 2015–16.
Women's collegiate basketball (at the time sanctioned by the
Commission on Intercollegiate Athletics for Women) used a 30-second shot clock on an experimental basis in the 1969–70 season, officially adopting it for the 1970–71 season.
The NCAA specifies 20 seconds rather than 30 after stoppages where the ball is already in the frontcourt. In 2019, it added offensive rebounds to this list.
US high schools rules
The
National Federation of State High School Associations
The National Federation of State High School Associations (NFHS) is the body that writes the rules of competition for most high school sports and activities in the United States. NFHS's headquarters are located in White River State Park in Indi ...
(NFHS), which sets rules for high school basketball in the U.S., does not mandate the use of a shot clock, instead leaving the choice to use a clock and its duration up to each individual state association. In concert with this, the "stall ball" strategy can be used in a state or league, but depending on the organization, itself comes with restrictions on its use by the game officials, with overuse of it often being whistled as a foul or an unsportsmanlike act. Others may allow stalling completely, at the risk of fan disinterest.
As the cost of a shot clock system can be cost-prohibitive, its use in high schools has been debated on that consideration and not the flow of the game. While previous proposals for a national shot clock had been denied by the NFHS as recently as 2011,
in the spring of 2021 the NFHS agreed to allow its member associations the option of a shot clock, with a mandatory 35-second duration, starting in 2022–23.
As of August 2021, 11 states either require a shot clock in high school competition or will begin using one starting in 2022–23: California, Georgia, Iowa, Maryland, Massachusetts, Nebraska (Class A only, expanded to Class B in 2023-24 and to all classes in 2024-25), New York, North Dakota, Rhode Island, South Dakota, and Washington.
Before 2022–23, the District of Columbia used a 30-second shot clock for public school (DCIAA) competition, charter school competition (as of 2018–19), and for the DCSAA State Tournament, where public, private, and charter schools compete for the championship of the District of Columbia.
Shot clock length
Shot clock length in basketball
Shot clock length in other sports
Related concepts
A related rule to speed up play is that the offensive team has a limited time to advance the ball across the half-court line (the " time line").
See also
*Pitch clock
A pitch clock (also known as a pitch timer) is used in various baseball leagues to limit the amount of time a pitcher takes before throwing the ball to the Batting (baseball), hitter and/or limit the amount of time the hitter uses before he is s ...
, used in baseball
* Play clock, used in American and Canadian football.
*Four corners offense
The four corners offense, also known as the four corner stall or the four corners delay offense, is an offensive strategy for stalling in basketball, primarily used in college basketball and high school basketball before the shot clock was institu ...
, offensive stall strategy in basketball
* Stall count, used in the sport of Ultimate
Ultimate or Ultimates may refer to:
Arts, entertainment, and media Music Albums
*Ultimate (Bryan Adams album), ''Ultimate'' (Bryan Adams album)
*Ultimate (Jolin Tsai album), ''Ultimate'' (Jolin Tsai album)
*Ultimate (Pet Shop Boys album), ''Ult ...
.
References
External links
*
24 Seconds to Shoot
snopes.com
{{DEFAULTSORT:Shot Clock
Basketball terminology
Basketball equipment
Rules of basketball
Timers
Basketball in Syracuse, New York
Snooker terminology
Time measurement systems