Shot clock

After Mitch McGary attempts a finger roll layup late in the first half of the 2012–13 Big Ten Conference men's basketball season opener on January 3 (left), the Michigan Wolverines and Northwestern Wildcats anticipate (center) and pursue (right) the rebound. The possession demonstrates the end-of-half intricacies of the National Collegiate Athletic Association's former 35-second shot clock (red LED) when possession changes and the game clock (white LED; note the decimal point) is below 35 seconds.

A shot clock is used in basketball to quicken the pace of the game. The shot clock times a play and provides that a team on offense that does not promptly try to score points loses possession of the ball. It is distinct from the game clock, which times the entire game. The shot clock may be referred to by its initial value. For example, in the National Basketball Association (NBA), it may be called the "24-second clock".

A shot clock is also used in snooker, men's lacrosse, water polo, korfball, and ten-pin bowling. It is analogous with the play clock used in American and Canadian football, and the pitch clock used in baseball.


The shot clock is a digital clock that displays a number of seconds. 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 beaters should be counted. The NBA specifies that a transparent shot clock and game clock 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 (LEDs) on the backboard. The NBA (since 2011), FIBA (since July 2018) and the Olympics (come 2020) require this.

In the final five seconds to shoot, the shot clock displays tenths of seconds. This was adopted in the 2011–12 NBA season,[1] 2014–15 Euroleague, FIBA since 2018, and the Olympics will do so in 2021.


The NBA has had a 24-second limit since 1954. FIBA introduced a 30-second shot clock in 1956 and switched to 24 seconds in 2000. The Women's National Basketball Association (WNBA) had a 30-second clock originally and switched to 24 seconds in 2006. Collegiate basketball uses a 30-second shot clock (details below).


Stall tactics to limit big man George Mikan (#99) led to the shot clock's creation by the NBA.

The NBA had problems attracting fans (and positive media coverage) before the shot clock's inception.[2]:23–31 Teams in the lead were running out the clock, 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 by a record-low score of 19–18, including 3–1 in the fourth quarter.[3] 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. It led the St. Paul Dispatch to write, "[The Pistons] gave pro basketball a great black eye."[4]:31–2 NBA President Maurice Podoloff said, "In our game, with the number of stars we have, we of necessity run up big scores."[4]:33 A few weeks after the Pistons/Lakers game, the Rochester Royals 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.


In 1954 in Syracuse, New York, Syracuse Nationals (now the Philadelphia 76ers) owner Danny Biasone and general manager Leo Ferris experimented with a 24-second shot clock during a scrimmage.[5][6] 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.[7] 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."[3][8][2]:29 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.

Use and reactionEdit

The Shot Clock Monument in Syracuse, New York.
Close-up of Syracuse's Shot Clock Monument.

When it was introduced by the NBA, the 24-second shot clock made players so nervous that it hardly came into play, as players were taking fewer than 20 seconds to shoot. According to Syracuse star Dolph Schayes, "We thought we had to take quick shots – a pass and a shot was it – maybe 8–10 seconds... But as the game went on, we saw the inherent genius in Danny's 24 seconds – you could work the ball around [the offensive zone] for a good shot."[2]:29

The shot clock, together with some rule changes concerning fouls, revolutionized NBA basketball. In the last pre-clock season (1953–54), teams averaged 79 points per game; in the first year with the clock (1954–55), the average was 93 points,[3] which went up to 107 points by its fourth year in use (1957–58).[2]:28 The advent of the shot clock (and the resulting increase in scoring) coincided with an increase in attendance, which increased 40% within a few years to an average of 4,800 per game.[4]:33–4

The shot clock received near-universal praise for its role in improving the style of play in the NBA. Coach and referee Charley Eckman said, "Danny Biasone saved the NBA with the 24-second rule."[9] Boston Celtic all-star Bob Cousy said, "Before the new rule, the last quarter could be deadly. The team in front would hold the ball indefinitely, and the only way you could get it was by fouling somebody. In the meantime, nobody dared take a shot and the whole game slowed up. With the clock, we have constant action. I think it saved the NBA at that time. It allowed the game to breathe and progress."[10] League president Maurice Podoloff called the adoption of the shot clock "the most important event in the NBA."[3] The league itself states, "Biasone's invention rescue[d] the league."[9]

Adoption by other leaguesEdit

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 (1961–1963). The American Basketball Association also adopted a 30-second clock when it launched in 1967–68, switching to the NBA's 24-second length for its final season (1975–76).

From its inception in 1975, the Philippine Basketball Association adopted a 25-second shot clock. This was because the shot clocks then installed at the league's main venues, the Araneta Coliseum and Rizal Memorial Coliseum (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 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.


The shot clock is reset to a certain number of seconds (usually 24) when the ball touches the rim or goes into the basket; and when possession of the ball switches to the other team, such as with a rebound, steal, or violation. The initial setting varies by country, level of play, and league; see the table below. In some cases, such as when the new offensive team does not have to travel the entire length of the court, the initial setting may be lower. The shot clock does not start to count down until a player achieves control of the ball, or in the case of a made basket, a player achieves control of the in-bounds pass.

The offensive team must shoot the ball before the shot clock expires. If the shot clock expires before the ball leaves the player's hand, the team has committed a shot clock violation that results in a turnover to their opponents. The buzzer may sound after the ball leaves the shooter's hand; this is not a violation.

Near the end of a period, if the shot clock would ordinarily display more time than the game clock, the shot clock is switched off (not to 0.0). The game clock shows how much time players have to shoot, because a shot must leave the hand before the end of the period.

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 introduced technology to unify the keeping of the shot clock and the game clock.[11] Tissot also became official timekeeper for the WNBA in the 2017 season.

14-second clockEdit

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 does not need a full 24 seconds. The shot clock is instead set to 14 following an offensive rebound.[12]:7-IV-d FIBA adopted this in 2014 and the NBA adopted in 2018.[13] 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.[12]:7-IV-e 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 and the (W)NBA, the shot clock is topped up to 14 seconds, as described above for a frontcourt inbounds pass.

Collegiate rulesEdit

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 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 win over Temple in 1973, support for a men's shot clock began to build.[14] The NCAA introduced the 45-second shot for the 1985–86 season;[15] several conferences had experimented with it for the two seasons prior.[16] It was reduced to 35 seconds in the 1993–94 season,[17] and 30 seconds in the 2015–16 season.[18] The NAIA also reduced the shot clock to 30 seconds starting in 2015–16.[19]

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.[20]

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.[21]

Scholastic rulesEdit

The National Federation of State High School Associations (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. Proposals to adopt a national shot clock for high school basketball have been voted down by the NFHS as recently as 2011.[22]

Eight U.S. states require the use of a shot clock of 30 or 35 seconds in high school competition: California, Maryland, Massachusetts, New York, North Dakota, Rhode Island, South Dakota, and Washington.[22] The District of Columbia also uses 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 in basketballEdit

Organization Duration
NBA 24 seconds (but see 14-second clock above)
U Sports (Canadian universities)
NCAA, NAIA, USCAA, et al. 30 seconds
United States high school basketball 30/35 seconds (some states only)
FIBA 24 seconds (but see 14-second clock above)
12 seconds (3x3 half-court)[23]

Shot clock length in other sportsEdit

Sport Organization Duration
Lacrosse MLL 60 seconds
PLL 52 seconds
NLL 30 seconds
NCAA Men's 80 seconds[24]
NCAA Women's 90 seconds[24]
Ringette N/A 30 seconds
Water polo FINA 30 seconds
Canoe polo ICF 60 seconds
Ten-pin bowling PBA 25 seconds (only used on TV)
Korfball IKF 25 seconds
Snooker Snooker Shoot Out 15 seconds (first five minutes)
10 seconds (last five minutes)
Carom billiards
(three-cushion billiards)
World Championship
European Championship
World Cup
40 seconds[25]
(3 time-outs (40 sec.) possible)
Poker World Poker Tour 30 seconds
99 seconds (optional)[26]

Related conceptsEdit

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 alsoEdit


  1. ^ Zillgitt, Jeff (December 24, 2011). "New points of emphasis in NBA officiating". USA Today. Retrieved February 4, 2012.
  2. ^ a b c d Pluto, Terry (1992). Tall Tales: The Glory Years of the NBA, in the Words of the Men Who Played, Coached, and Built Pro Basketball.
  3. ^ a b c d "History of the Shot Clock" Archived April 24, 2012, at the Wayback Machine NBA.
  4. ^ a b c Pomerantz, Gary M. (2005). Wilt, 1962: The Night of 100 Points and the Dawn of a New Era. New York: Crown. ISBN 1-4000-5160-6.
  5. ^ " 24-Second Shot Clock Rescues League". Retrieved November 3, 2015.
  6. ^ "National efforts to honor Syracuse hoops pioneers: Good day to remember Earl Lloyd, Leo Ferris". Retrieved November 3, 2015.
  7. ^ "A question for a Hall of Fame dinner in Syracuse: When will Leo Ferris make it in?". Retrieved November 3, 2015.
  8. ^ "Long-forgotten Leo Ferris helped devise NBA's 24-second clock, first used 61 years ago today". Retrieved November 3, 2015.
  9. ^ a b "1954–55 SEASON OVERVIEW" NBA.
  10. ^ "History of the Shot Clock". NBA Media Ventures, LLC. Archived from the original on April 24, 2012. Retrieved April 8, 2013.
  11. ^ "NBA, watchmaker Tissot announce multiyear partnership". ESPN. Retrieved February 23, 2016.
  12. ^ a b "RULE NO. 7: Shot Clock". NBA.
  13. ^ NBA implements FIBA's 14-second shot clock rule,
  14. ^ Strange, Mike (2007-11-07). "Temple set stage for shot clock". The Knoxville News-Sentinel. Scripps Interactive Newspaper Group. Archived from the original on November 9, 2007. Retrieved January 13, 2012.
  15. ^ Crowley, Anne S. (April 3, 1985). "NCAA adopts shot clock for next year". Spokesman-Review. (Spokane, Washington). Associated Press. p. C3.
  16. ^ Cour, Jim (April 5, 1984). "Shot clock put on hold by colleges". Spokesman-Review. (Spokane, Washington). Associated Press. p. 25.
  17. ^ Official 2008 NCAA Men's Basketball Records Book, p. 278
  18. ^ "Shorter shot clock, fewer timeouts among changes coming in 2015-16". June 8, 2015. Retrieved June 9, 2015.
  19. ^ "Rule changes for NAIA, too". The Salina Journal. Associated Press. June 10, 2015 – via News OK.
  20. ^ Official 2008 NCAA Women's Basketball Records Book, p. 245
  21. ^ Katz, Andy (November 5, 2019). "The men's college basketball rule changes to know about this season". NCAA.
  22. ^ a b Halley, Jim (May 5, 2011). "Focus on high school shot clock heats up as states make move –". USA Today. ISSN 0734-7456. Retrieved December 31, 2011.
  23. ^ "Article 8 Stalling" (PDF). 3x3 Rules of the Game. FIBA. January 13, 2012. p. 2. Retrieved April 11, 2013.
  24. ^ a b Lee, Edward (September 12, 2018). "Time is now: NCAA approves 80-second shot clock for men's lacrosse". The Baltimore Sun. Retrieved February 13, 2019.
  25. ^ "Official Tournament Rules" (PDF). Union Mondiale de Billard (UMB). p. 4. Retrieved April 30, 2017.
  26. ^ " Poker Shot Clock". Retrieved January 30, 2020.

External linksEdit