Instant replay

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Instant replay is a video reproduction of something that recently occurred which was both shot and broadcast live. The video, having already been shown live, is replayed in order for viewers to see again and analyze what had just taken place. Some sports allow officiating calls to be overturned after the review of a play. Instant replay is most commonly used in sports, but is also used in other fields of live TV. While the first near-instant replay system was developed and used in Canada, the first instant replay was developed and deployed in the United States.


During a 1955 Hockey Night in Canada broadcast on CBC Television, producer George Retzlaff used a "wet-film" (kinescope) replay, which aired several minutes later. Videotape was introduced in 1956 with the Ampex Quadruplex system. However, it was incapable of displaying slow motion, instant replay, or freeze-frames, and it was difficult to rewind and set index points.

CBS Sports Director Tony Verna invented a system to enable a standard videotape machine to instantly replay on December 7, 1963, for the network's coverage of the Army–Navy Game. The instant replay machine weighed 1,300 pounds (590 kg).[1] After technical hitches, the only replay broadcast was Rollie Stichweh's touchdown. It was replayed at the original speed, with commentator Lindsey Nelson advising viewers "Ladies and gentlemen, Army did not score again!"[1] The problem with older technology was the difficulty of finding the desired starting point; Verna's system used audio tones activated as an interesting event unfolded, which technicians could hear during the rewinding process.

Replay from analog disk storage was tried out by CBS in 1965, and commercialized in 1967 by the Ampex HS-100, which had a 30-second capacity and freeze frame capability.[2]

Instant replay has been credited as a primary factor in the rise of televised American football, although it was popular on television even before then. While one camera was set up to show the overall “live” action, other cameras, which were linked to a separate videotape machine, framed close-ups of key players. Within a few seconds of a crucial play, the videotape machine would replay the action from various, close-up angles, in slow motion.[3]

Prior to instant replay, it was almost impossible to portray the essence of an American football game on television. Viewers struggled to assimilate the action from a wide shot of the field, on a small black-and-white television screen. However, with replay technology, “brutal collisions became ballets, and end runs and forward passes became miracles of human coordination.” Thanks in large part to instant replay, televised football became evening entertainment, perfected by ABC-TV’s Monday Night Football, and enjoyed by a wide audience[3]

Marshall McLuhan, the noted communication theorist, famously said that any new medium contains all prior media within it. McLuhan gave Tony Verna's invention of instant replay as a good example. "Until the advent of the instant replay, televised football had served simply as a substitute for physically attending the game; the advent of instant replay – which is possible only with the television – marks a post-convergent moment in the medium of television."

In television

In television broadcasting of sports events, instant replay is often used during live broadcast, to show a passage of play which was important or remarkable, or which was unclear on first sight.

Replays are typically shown during a break or lull in the action; in modern telecasts, it will be the next break, though older systems were sometimes less instant. The replay may be in slow motion, or from multiple camera angles.

Video servers, with their advanced technology, have allowed for more complex replays, such as freeze frame, frame-by-frame review, replay at variable speeds, overlaying of virtual graphics, instant analysis tools such as ball speed or immediate distance calculation. Sports commentators analyze the replay footage when it is being played, rather than describing the concurrent live action.

Instant replays are used today in broadcasting extreme sports, where the speed of the action is too high to be easily interpreted by the naked eye, using combinations of advanced technologies such as video servers and high-speed cameras recording at up to several thousand frames per second.

Use by officials

Some sports organizations allow referees or other officials to consult replay footage before making or revising a decision about an unclear or dubious play. This is variously called video referee, video umpire, instant replay official, television match official or third umpire. Other organizations allow video evidence only after the end of the contest, for example to penalize a player for misconduct not noticed by the officials during play.

Leagues using instant replay in official decision making include the National Hockey League, National Football League, Canadian Football League, National Basketball Association, and Major League Baseball. The role of the video referee differs varies; often they can only be called upon to adjudicate on specific events. Due to the cost of television cameras and other equipment needed for a video referee to function, most sports only employ them at a professional or top-class level.

Gridiron football codes


In NBA basketball, the officials must watch an instant replay of a potential buzzer beater to determine if the shot was released before time expired. Since 2002, the NBA has mandated installation of LED light strips on both the backboard and the scorer's table that illuminate when time expires, to assist with any potential review.

Instant replay first came to NBA in the 2002–03 season. In Game 4 of the 2002 Western Conference Finals, Los Angeles Lakers forward Samaki Walker made a three-point field goal from the half court at the end of the second quarter. However, the replay showed that Walker's shot was late and that the ball was still in his hand when the clock expired. The use of instant replay was instituted afterward.[4]

Beginning with the 2007–08 season, replay also can be used in determining players being ejected from contests involving brawls or flagrant fouls. In the 2008–09 season, replay may also be used to correctly determine whether a scored field goal is worth two or three points. It may also be used to determine the correct number of free throws awarded for a missed field goal. It may also be used in cases where the game clock malfunctions and play continues to decide how much time to take off the clock.[5]

In college basketball, the same procedure may also be used to determine if a shot was released before time expired in either half or an overtime period. In addition, NCAA rules allow the officials to use instant replay to determine if a field goal is worth two or three points, who is to take a free throw, whether a fight occurred and who participated in a fight. The officials may also check if the shot was made before the expiration of the shot clock, but only when such a situation occurs at the end of a half or an overtime period. Such rules have required the NCAA to write new rules stating that, when looking at instant replay video, the zeros on the clock, not the horn or red light, determine the end of the game.

In Italy, host broadcaster Sky agreed with Serie A to the adoption of instant replay for special tournaments and playoff games, and in 2005, for the entire season. Instant replay would be used automatically on situations similar to the NCAA, but coaches may, like the NFL, have one coach's challenge to challenge a two or three point shot. Officials may determine who last touched the ball in an out-of-bounds situation or back-court violations.

The adoption of instant replay was crucial in the 2005 Serie A championship between Armani Jeans Milano and Climamio Bologna. Bologna led the best-of-five series, 2-1, with Game 4 in Milan, and the home team leading 65-64, as Climamio's Ruben Douglas connected on a three-point basket at the end of the game to apparently win the Serie A championship.

Officials, knowing the 12,000 fans on both sides would learn the fate of the series on their call, watched replays of the shot before determining it was valid.

The Euroleague Basketball (company) adopted instant replay for the 2006 Euroleague Final Four and made a rule change determining the lights on the backboard, not the horn, will end a period, thus assisting with instant replay.[6]

On April 6, 2006, FIBA announced instant replay for last-second shots would be legal for their competitions.

"The referee may use technical equipment to determine on a last shot made at the end of each period or extra period, whether the ball has or has not left the player's hand(s) within the playing time."[7]

Before the beginning of the 2013-2014 NBA season, new instant replay rules were put into effect, saying that it can be used for: block/charge plays; to determine if an off-ball foul occurred before or after a shooting motion began in a successful shot attempt, or if the ball is released on a throw in. They also began to use instant reply to determine correct penalties for flagrant fouls. [8]

Ice hockey

The video goal judge reviews replays of disputed goals. As the referee does not have access to television monitors, the video goal judge's decision in disputed goals is taken as final. In the NHL, goals may only be reviewed in the following situations: puck crossing the goal line completely and before time expired, puck in the net prior to goal frame being dislodged, puck being directed into the net by hand or foot, puck deflected into the net off an official, and puck deflected into the goal by a high stick (stick above the goal) by an attacking player. All NHL goals are subject to review, and although most arenas have a video goal judge, often officials in the Situation Room (also known as the "War Room") at the NHL office in Toronto make the final decision.

Instant replay review challenges

Beginning in the 2015-16 NHL season, instant replay reviews have been expanded to include a coach's challenge. Each coach receives one challenge per game, which requires the use of a timeout. Coaches may only challenge over situations whether the goal should have been disallowed because of goaltender interference or an offside, or whether a goal disallowed because of goaltender interference should be allowed instead. The challenging team retains its timeout and its challenge after every call that has been overturned. Unsuccessful challenges result in the loss of the challenging team's timeout. Challenges are not allowed during the final minute of regulation, as well as at any point during overtime. In this situation, officials in the Situation Room reviews all instances where the puck entered the net, and then determines the final ruling. However, for reviews that take place during coach's challenges, the on-ice officials determine the final ruling.

Field hockey

In field hockey, the International Hockey Federation allows the match umpire to request the opinion of a video umpire as to whether or not a goal has been validly scored, and whether there was a violation in the build-up to a goal.[9] The video umpire can advise on whether the ball crossed the line there was a violation.[9] Ordinarily, teams are not allowed to make such a request or to press the match umpire to do so.[9] On a trial basis, the 2009 Men’s Champions Trophy allows for "team referral" by each team captain, to query a goal, penalty stroke, or penalty corner decision. The team retains the right to a referral if its previous referrals were upheld.[10]


Umpires in St.Louis await the ruling.

In Major League Baseball, instant replay has been introduced to address "boundary calls," which include questions on whether or not a hit should be considered a home run (HR). Among reviewable plays are: Fair Ball-HR; Foul Ball, Ball Clearing Wall-HR; Ball Staying in Play-Live Ball; Ball Leaving Field of Play-HR; and, Ball or Player interfered with by spectators (called Spectator Interference). The latest MLB collective bargaining agreement, pending agreement by the umpires' union, expands instant replay to include: Fair Ball; Foul Ball along foul lines, or Ball Caught for Out; Ball Trapped Against Ground or Wall; as well as expanding Interference calls to all walls regardless of whether it is a "boundary call" or not.

In Little League Baseball, Instant Replay was adopted for the Little League World Series only, and includes all "boundary call" plays reviewable at the Major League Level, in addition to adding review to plays involving force outs, tag plays on the basepaths, hit batters, and for defensive appeals regarding whether a runner missed touching a base.[11]


In tennis, systems such as Hawk-Eye and MacCAM calculate the trajectory of the ball by processing the input of several video cameras. They can play a computer rendering of the path and determine whether the ball landed in or out. Players can appeal to have the system's calculation used to override a disputed call by the umpire. In March 2008, the International Tennis Federation, Association of Tennis Professionals, Women's Tennis Association and Grand Slam Committee agreed unified challenge rules: a player can make up to three unsuccessful challenges per set, and a fourth in a tie-break.[12] Television broadcasts may use the footage to replay points even when not challenged by a player.

Rugby league

The video referee confirms a Try during an Australia vs Great Britain match in the 2006 Rugby League Tri-Nations

Since being introduced by Europe's Super League in 1996,[13] video referees have been adopted in Australia's National Rugby League and international competition as well. In rugby league the video referee can be called upon by the match official to determine the outcome of a possible try. The "video ref" can make judgements on knock-ons, offside, obstructions, hold-ups and whether or not a player has gone dead, but cannot rule on a forward pass. If a forward pass has gone un-noticed by the on-field officials it must be disregarded by the video ref, as such judgements cannot reliably be made due to camera angle effects.

Rugby union

Use of video referee was introduced to rugby union in 2001.[14] The laws of the game allow for "an official who uses technological devices" to be consulted by the referee in decisions relating to scoring a try or a kick at goal.[15] The decision to call on the video referee (now called "Television Match Official (TMO)") is made by the referee, then the call is made by the replay referee, who takes his place in the stand of the host team or more usually in the Television Outside Broadcast van. He either tells the pitch referee by radio link-up or by the use of a big screen during televised matches. Unlike in the NFL, a coach cannot challenge a call made by the pitch referee.


Cricket also uses an instant replay. It is used in the areas of run outs, stumpings, doubtful catches and whether the ball has crossed the boundary for a six or short of a four.

The International Cricket Council[16] decided to trial a referral system during the Indian tour of Sri Lanka through late July and August 2008. This new referral system allows players to seek reviews, by the third umpire, of decisions by the on-field umpires on whether or not a batsman has been dismissed. Each team can make three[citation needed] unsuccessful requests per innings, which must be made within a few seconds of the ball becoming dead; once made, the requests cannot be withdrawn. Only the batsman involved in a dismissal can ask for a review of an "out" decision; in a "not out", only the captain or acting captain of the fielding team. In both cases players can consult on-field teammates but signals from off the field are not permitted.

A review request can be made by the player with a 'T' sign; the umpire will consult the TV umpire, who will review TV coverage of the incident before relaying back fact-based information. The field umpire can then either reverse his decision or stand by it; he indicates "out" with a raised finger and "not out" by crossing his hands in a horizontal position side to side in front and above his waist three times.

The TV umpire can use regular slow-motion, or high-speed camera angles usually called ultra-motion or super-slow replays, the mat, sound from the stump mics and approved ball tracking technology, which refers to Hawk-Eye technology that would only show the TV umpire where the ball pitched and where it hit the batsman's leg and it is not to be used for predicting the height or the direction of the ball. Snicko and Hot Spot can also be used.

Ultra Motion or Slo-mo is the predecessor of Hi Motion, its superior and easier-to-use successor which was started in 2006, Ultra Motion shot at 1000 frames a second to produced some remarkable images. For the first time viewers could see the amazing way that bats bent and twisted as they made contact with the ball, and even the way the bones in the hand reverberate when a catch is made. Perhaps it is at its most useful when used to show just where on the batsman's bat or body a ball glanced, rarely does a replay fail to clear that issue up. Often used by TV productions during closing sequences or musical interludes. The latest addition that is not yet widespread used is the super slow motion cameras, showing the frames that are missed out by the regular cameras.


The Professional Bull Riders organization, beginning with the 2006–07 season, has instituted an instant replay system in cooperation with the Versus network.

A bull rider, a fellow competitor, or a judge may request a replay review by filing a protest to the replay official within 30 seconds of any decision.

Any competitor (it does not have to be the rider who is riding the bull in question, as fellow riders can observe the action and spot fouls by bull or rider) may file the complaint to the replay official by sounding a signal at the arena and pay a fee of $500 to PBR before explaining to the replay official why he is filing the request.

The replay official (usually a former bull rider) may request different angles and/or slow motion, as well as freeze particular frames. The replay judge will use all available technology to assess the call in question and supply his ruling. This includes using his own hand-held stopwatch to time bull rides, as the official eight-second clock used in PBR competition starts when the bull usually exits the bucking chute.

The replay will be used to evaluate timing issues, fouls against the rider for touching the bull or ground with his free hand or using the fence to stay on the bull, or fouls by the bull, such as dragging the rider across the fence.

If an appeal is successful, the $500 is returned to the competitor filing the request. If the appeal is unsuccessful, the $500 is forfeited and sent to PBR charities such as the Resistol Relief Fund to assist injured bull riders.

Motor sports

NASCAR utilizes instant replay to supplement their electronic scoring system. Video replays are used to review rules infractions and scoring disputes.

  • Video replay supplements electronic scoring at the finish line (particularly the race winner) in "photo finish" situations.
  • Video replay supplements electronic scoring to determine the final positions when a race ends with a caution flag on the last lap or under a green-white-checker finish.
  • Video replay is used to determine if a car has crossed the pit entrance before the pit was closed for a yellow flag. It also determines if drivers are following pit road speed limits.
  • Video replay supplements electronic scoring to determine the positions in which cars exit the pits (during cautions).

IndyCar also utilizes instant replay for similar reasons.

  • The most notable use of replay in recent years occurred during the 2008 Peak 300 at Chicagoland Speedway. On the final lap, Scott Dixon and Helio Castroneves crossed the finish line side by side, with computer scoring showing Dixon the winner by a margin of 0.0010 seconds. However, video replay evidence clearly showed that the nose of Castroneves' car touched the line first. Castroneves was declared the winner officially by 0.0033 seconds or 12⅛ inches, in the second closest finish in the twelve-year history of the series.[17] It was later determined that the deliberate improper installation of Dixon's scoring transponder was the source of the scoring error.
  • Video replay was also used extensively in the aftermath of the controversial 2002 Indianapolis 500. However, fully conclusive evidence was lacking.

Broadcast stations utilize replays to show viewers a crash in greater detail.[18]

Association football

In association football, FIFA does not permit video evidence during matches, although it is permitted for subsequent disciplinary sanctions.[19] The 1970 meeting of the International Football Association Board "agreed to request the television authorities to refrain from any slow-motion play-back which reflected, or might reflect, adversely on any decision of the referee".[20] In 2005, Urs Linsi, general secretary of FIFA, said:[21]

Players, coaches and referees all make mistakes. It's part of the game. It's what I would call the "first match". What you see after the fact on video simply doesn't come into it; that's the "second match", if you like. Video evidence is useful for disciplinary sanctions, but that's all. As we've always emphasised at FIFA, football's human element must be retained. It mirrors life itself and we have to protect it.

There have been allegations that referees had made or changed decisions on the advice of a fourth official who had seen the in-stadium replay of an incident. This was denied by FIFA in relation to the Zidane headbutt of Materazzi in the 2006 World Cup final,[22] and in relation to the 2009 FIFA Confederations Cup match between Brazil and Egypt, in which Howard Webb signalled initially for a corner kick but then a penalty kick.[23][24]

It has been said that instant replay is needed given the difficulty of tracking the activities of 22 players on such a large field,[25] FIFA officials approached researchers at the University of Glasgow in Scotland for help, but came up with nothing that could satisfy the league's stringent requirements.[26] Opponents of instant replay like FIFA President Sepp Blatter argue that refereeing mistakes add to the "fascination and popularity of football."[27] It has been proposed that instant replay be limited to use in penalty incidents, fouls which lead to bookings or red cards and whether the ball has crossed the goal line, since those events are more likely than others to be game-changing.[28]

In 2007, FIFA authorized tests of two systems, one involving an implanted chip in the ball and the other using a modified version of Tennis's Hawk-Eye system, to assist referees in deciding whether a ball had crossed over the goal line.[29] The following year, however, the IFAB and FIFA halted testing of all goal line technology, fearing that its success would lead to its possibly expansion to other parts of the game. Sepp Blatter claimed the technologies were flawed and too expensive to be implemented on a widespread basis, adding, "Let it be as it is and let's leave (soccer) with errors. The television companies will have the right to say (the referee) was right or wrong, but still the referee makes the decision — a man, not a machine." This sudden change of course surprised and angered Paul Hawkins, as the inventor of the Hawk-Eye system had invested a great deal of money into adapting the Hawk-Eye technology to football.[27] In 2009, Hawkins sent an open letter to Blatter refuting the FIFA president's assertion that the Hawk-Eye goal line technology was flawed and arguing that Hawk-Eye met all of the criteria established by the IFAB for a suitable goal line technology system.[30]

The controversy over goal line technology was re-ignited in 2009 after Brazil had a potential equalizing goal disallowed during the 2009 Confederations Cup Final; and during the 2010 FIFA World Cup after England's Frank Lampard's shot off the underside of the crossbar during a 4-1 defeat against Germany was not ruled a goal, despite replays clearly showing it was 60 cm over the line.[31][32]

See also


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  2. Howe, Tom. "1967: Ampex Instant Replay Disk Recorder". CED Magic. Portland, Oregon. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  3. 3.0 3.1 Barnouw, E. (1990). Tube of plenty : the evolution of American television / Erik Barnouw. New York : Oxford University Press, 1990.
  4. "Pro Basketball; N.B.A. Will Use Replay To Review Buzzer Shots". The New York Times. July 30, 2002. Retrieved May 24, 2011.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  5. "Djbescription of the NBA's new instant replay rules". 23 October 2008. Retrieved 16 November 2008.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  6. League officials work with Sky TV for technical progress
  7. FIBA accepts video proof for last second shots
  8. NBA approves of five new rules changes for 2013-14 season
  9. 9.0 9.1 9.2 "FIH Tournament Regulations: Outdoor Competitions" (PDF). FIH. November 2009. p. 9: §13. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>[dead link]
  10. FIH Tournament Regulations, p.30: Appendix 6, §2.2
  11. Baxter, Kevin (August 2, 2010). "Little League to expand instant replay". Los Angeles Times. Retrieved May 24, 2011.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  12. "Hawk-Eye challenge rules unified". BBC. 19 March 2008. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  13. Reuter (8 October 1996). "Aussie rebels to follow Euro lead". New Straits Times. Retrieved 2 June 2012.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  14. Cleary, Mick (4 April 2001). "World Cup play-offs abandoned". The Telegraph. Retrieved 2 June 2012.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  15. "6.A.7 Referee consulting with others". IRB Laws of the Game (PDF). Dublin: International Rugby Board. 2007. p. 22. ISBN 0-9552232-4-5. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  16. Trial Playing Condition - Review of Umpiring Decisions
  17. "Champion Dixon shrugs off race loss". 2008-09-08. Archived from the original on September 11, 2008. Retrieved 2008-09-08. Unknown parameter |deadurl= ignored (help)<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  18. NASCAR replays with EVS servers
  19. "Fifa rules out video evidence". The Guardian. London. 5 January 2005. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  20. IFAB (27 June 1970). "Minutes of the AGM" (PDF). Inverness: Soccer South Bay Referee Association. p. §5(i). Retrieved 29 November 2009. Invalid |nopp=Y (help)<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  21. "Urs Linsi: We expect another great success this year". FIFA. 10 June 2005. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  22. Scott, Matt (12 July 2006). "Materazzi joins Zidane as target of Fifa inquiry". The Guardian. London. Retrieved 29 November 2009. Fifa has strongly denied allegations that the Argentinian referee Horacio Elizondo had missed the incident and dismissed the France captain only after the fourth official alerted him on seeing a television replay.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  23. "Fifa rejects Egypt protest over Howard Webb penalty decision". The Guardian. London. 16 June 2009. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  24. "Fifa removes sideline monitors after Howard Webb penalty row in Confederations Cup". The Guardian. London. 18 June 2009. Retrieved 29 November 2009.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  25. Van Buskirk, Eliot (November 30, 2009). "Soccer Resists Instant Replay Despite Criticism". Wired. Retrieved May 24, 2011.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  26. Borland, John (June 19, 2006). "World Cup soccer loves to hate high tech". Retrieved May 24, 2011.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  27. 27.0 27.1 "FIFA halts instant replay experiment". CBC Sports. 8 March 2008. Retrieved 28 June 2010.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  28. "Instant replay may be a good idea, but it's a tricky one - Gabriele Marcotti -". CNN. 25 September 2008.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  29. Dickinson, Matt (17 August 2007). "Hawk-Eye set to extend its influence to contested goals". The Times. London. Retrieved 28 June 2010.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  30. Dr. Paul Hawkins (22 September 2009). "Open Letter" (PDF). Retrieved 28 June 2010.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  31. "Kaka 'goal' ramps up debate over Hawk-Eye's role in football". Sports Features Communications. 29 June 2009. Retrieved 28 June 2010.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>
  32. Vecsey, George (27 June 2010). "An Obvious Case for Instant Replay". New York Times. Retrieved 28 June 2010.<templatestyles src="Module:Citation/CS1/styles.css"></templatestyles>