Cricket The technology was first used by
Channel 4 during a
Test match between
England and
Pakistan on
Lord's Cricket Ground, on 21 May 2001. It is used by the majority of television networks to track the trajectory of balls in flight. Its major use in cricket broadcasting is in analysing
leg before wicket (LBW) decisions, where the likely path of the ball can be projected forward, through the
batsman's legs, to see if it would have hit the
stumps. In the winter season of 2008/2009 the
ICC trialled a referral system where Hawk-Eye was used for referring decisions to the third umpire if a team disagreed with an LBW decision. Initially the third umpire was able to look at what the ball actually did up to the point when it hit the batsman, but could not look at the predicted flight of the ball after it hit the batsman. The third umpire is now able to see the projected path of the ball too, and Hawk-Eye is currently sanctioned in international cricket even though some doubts remain about its accuracy. When an LBW decision is referred to Hawk-Eye, it assists in assessing against three criteria: • Where the ball pitched (in particular with respect to the stumps) • The location of impact on the leg of the batsman (in particular with respect to the stumps) • The projected path of the ball past the batsman In all three cases, marginal calls result in the on-field umpire's call being maintained. Due to its real-time coverage of bowling speed, the system is also used to show delivery patterns of a bowler's behaviour such as
line and length, or
swing/turn information. At the end of an
over, all six deliveries are often shown simultaneously to illustrate a bowler's variations, such as slower deliveries, bouncers and leg-cutters. A complete record of a bowler can also be shown over the course of a match. Batsmen also benefit from the analysis of Hawk-Eye, as a record can be brought up of the deliveries from which a batsman scored. These are often shown as a 2-D silhouetted figure of a batsman and colour-coded dots of the balls faced by the batsman. Information such as the exact spot where the ball pitches or speed of the ball from the bowler's hand (to gauge batsman reaction time) can also help in post-match analysis.
Tennis :
For a history of electronic line calling in tennis, see Electronic line judge In
Serena Williams's quarter final loss to
Jennifer Capriati at the
2004 US Open, three line calls went against Williams in the final set (an Auto-Ref system was being tested during the match). Though the calls were not reversed, there was one overrule of a clearly incorrect line umpire call, by the chair umpire
Mariana Alves, that the TV replay showed to be good. These errors prompted talks about line calling assistance especially as the Auto-Ref system was being tested by the U.S. Open at that time and was shown to be very accurate. In late 2006 Hawk-Eye was tested by the
International Tennis Federation (ITF) in New York City and was passed for professional use. Hawk-Eye reported that the New York tests involved 80 shots being measured by the ITF's high speed camera, a device similar to MacCAM. During an early test of the system at an exhibition tennis tournament in Australia (seen on local TV), there was an instance when the tennis ball was shown as "Out", but the accompanying word was "In". This was explained to be an error in the way the tennis ball was shown on the graphical display as a circle, rather than as an ellipse. This was immediately corrected. Hawk-Eye has been used in television coverage of several major tennis tournaments, including
Wimbledon, the
Queen's Club Championships, the Australian Open, the
Davis Cup and the
Tennis Masters Cup. The
US Open Tennis Championship announced they would make official use of the technology for the
2006 US Open where each player receives two challenges per set. It is also used as part of a larger tennis simulation implemented by
IBM called PointTracker. The
2006 Hopman Cup in
Perth, Western Australia, was the first elite-level tennis tournament where players were allowed to challenge point-ending line calls, which were then reviewed by the referees using Hawk-Eye technology. It used 10 cameras feeding information about ball position to the computers.
Jamea Jackson was the first player to challenge a call using the system. In March 2006, at the
Nasdaq-100 Open in
Key Biscayne, Florida, Hawk-Eye was used officially for the first time at a tennis tour event. Later that year, the
US Open became the first grand-slam tournament to use the system during play, allowing players to challenge line calls. The
2007 Australian Open was the next grand-slam event to implement Hawk-Eye in challenges to line calls, where each tennis player in Rod Laver Arena was allowed two incorrect challenges per set and one additional challenge should a tiebreak be played. In the event of an advantage final set, challenges were reset to two for each player every 12 games, i.e. 6-all, 12-all, etc. Controversies followed the event as at times Hawk-Eye produced erroneous output. In 2008, tennis players were allowed three incorrect challenges per set instead. Any leftover challenges did not carry over to the next set. Once,
Amélie Mauresmo challenged a ball that was called in, and Hawk-Eye showed the ball was out by less than a millimetre, but the call was allowed to stand. As a result, the point was replayed and Mauresmo did not lose an incorrect challenge. The Hawk-Eye technology used in the
2007 Dubai Tennis Championships had some minor controversies. Defending champion Rafael Nadal accused the system of incorrectly declaring an out ball to be in following his exit. The umpire had called a ball out; when
Mikhail Youzhny challenged the decision, Hawk-Eye said it was in by . Youzhny said after that he himself thought the mark may have been wide but then offered that this kind of technology error could easily have been made by linesmen and umpires. Nadal could only shrug, saying that had this system been on clay, the mark would have clearly shown Hawk-Eye to be wrong. The
2007 Wimbledon Championships also implemented the Hawk-Eye system as an officiating aid on
Centre Court and Court 1, and each tennis player was allowed three incorrect challenges per set. If the set produced a tiebreak, each player was given an additional challenge. Additionally, in the event of a final set (third set in women's or mixed matches, fifth set in men's matches), where there is no tiebreak, each player's number of challenges was reset to three if the game score reached 6–6, and again at 12–12.
Teymuraz Gabashvili, in his first round match against
Roger Federer, made the first-ever Hawk-Eye challenge on Centre Court. Additionally, during the finals of Federer against
Rafael Nadal, Nadal challenged a shot which was called out. Hawk-Eye showed the ball as in, just clipping the line. The reversal agitated Federer enough for him to request (unsuccessfully) that the umpire turn off the Hawk-Eye technology for the remainder of the match. In the
2009 Australian Open fourth round match between Roger Federer and
Tomáš Berdych, Berdych challenged an out call. The Hawk-Eye system was not available when he challenged, likely due to a particularly pronounced shadow on the court. As a result, the original call stood. In the
2009 Indian Wells Masters quarterfinals match between
Ivan Ljubičić and
Andy Murray, Murray challenged an out call. The Hawk-Eye system indicated that the ball landed on the centre of the line despite instant replay images showing that the ball was clearly out. It was later revealed that the Hawk-Eye system had mistakenly picked up the second bounce, which was on the line, instead of the first bounce of the ball. Immediately after the match, Murray apologised to Ljubicic for the call, and acknowledged that the point was out. The Hawk-Eye system was developed as a replay system, originally for TV broadcast coverage. As such, it initially could not call ins and outs live.The representation of the trajectory results in terms of where the ball lands is called
Shot Spot. The Hawk-Eye Innovations website states that the system performs with an average error of . The standard diameter of a tennis ball is , equating to a 5% error relative to ball diameter. This is roughly equivalent to the fluff on the ball. Hawk-Eye has developed a technology called 'Hawk-Eye Live', which uses the 10 cameras to call shots in or out in real time, with an 'out' call being signified by a speaker emitting an 'out' sound that emulates a human line judge. The technology was initially expected to be in place for the 2019 US Open. The
2021 Australian Open was the first Grand Slam tournament to use Hawk-Eye Live for all matches in place of line judges, in part to reduce personnel during the
COVID-19 pandemic, followed by the US Open later that year. Previously, the 2020 US Open used Hawk-Eye in place of line judges for all matches except those held at
Arthur Ashe Stadium and
Louis Armstrong Stadium. Clay court tournaments, notably the
French Open, are generally free of Hawk-Eye technology due to marks left on the clay where the ball bounced to evidence a disputed line call. Chair umpires are then required to get out of their seat and examine the mark on court with the player by their side to discuss the chair umpire's decision. The
2021 Mutua Madrid Open became the first major tournament on clay to use an electronic system to check the bounce of the ball on the court when in doubt in the two main stadiums (Manolo Santana Stadium and Arantxa Sánchez Vicario Stadium at
Caja Mágica). The system was developed by FoxTenn, a Spanish company located in
Barcelona. It uses real images of the ball captured by 40 cameras located at ground level, synchronized with lasers and working at up to 3,000 images per second to determine whether it has bounced in or out of the court's limits. This system was previously used at the
2020 Rio Open in
Rio de Janeiro and at the
2021 MUSC Health Women's Open in
Charleston, South Carolina.
Unification of rules Until March 2008, the International Tennis Federation (ITF),
Association of Tennis Professionals (ATP),
Women's Tennis Association (WTA),
Grand Slam Committee, and several individual tournaments had conflicting rules on how Hawk-Eye was to be utilised. A key example of this was the number of challenges a player was permitted per set, which varied among events. Some tournaments allowed players a greater margin for error, with players allowed an unlimited numbers of challenges over the course of a match.
Replacement of human line judges Since 2021 the Australian Open has used Hawk-Eye to call lines in all games. The US Open replaced line judges with full electronic line calls in 2022.
Association football Hawk-Eye is one of the
goal-line technology (GLT) systems authorised by
FIFA. Hawk-Eye tracks the ball, and informs the
referee if a ball fully crosses the goal line into the
goal. The purpose of the system is to eliminate errors in assessing if a
goal was scored. The Hawk-Eye system was one of the systems trialled by the sport's governors prior to the 2012 change to the
Laws of the Game that made GLT a permanent part of the game, and it has been used in various competitions since then. GLT is not compulsory and, owing to the cost of Hawk-Eye and its competitors, systems are only deployed in a few high-level competitions. , licensed Hawk-Eye systems were installed at 96 stadiums. By number of installations, Hawk-Eye is the most popular GLT system. Hawk-Eye is the system used in the
Premier League,
Serie A and
Bundesliga among other leagues.
Snooker At the
2007 World Snooker Championship, the
BBC used Hawk-Eye for the first time in its television coverage to show player views, particularly of potential snookers. It has also been used to demonstrate intended shots by players when the actual shot has gone awry. It is now used by the BBC at every World Championship, as well as some other major tournaments. The BBC used to use the system sporadically, for instance in the 2009 Masters at Wembley the Hawk-Eye was at most used once or twice per frame. Its usage has decreased significantly and is now only used within the World Championships and very rarely in any other tournament on the snooker tour. In contrast to tennis, Hawk-Eye is never used in snooker to assist referees' decisions and primarily used to assist viewers in showing what the player is facing.
Gaelic games In Ireland, Hawk-Eye was introduced for all championship matches at
Croke Park in
Dublin in 2013. This followed consideration by the
Gaelic Athletic Association (GAA) for its use in
Gaelic football and
hurling. A trial took place at Croke Park on 2 April 2011. The double-header featured football between
Dublin and
Down and hurling between
Dublin and
Kilkenny. Over the previous two seasons there had been many calls for the technology to be adopted, especially from Kildare fans, who saw two high-profile decisions go against their team in important games. The GAA said it would review the issue after the 2013
Sam Maguire Cup was presented. Hawk-Eye's use was intended to eliminate contentious scores. Its first use in the championship came on Saturday 1 June 2013 for the
Kildare v
Offaly game, part of a double header with a second game of
Dublin v
Westmeath. Hawk-Eye determined that Offaly substitute
Peter Cunningham's attempted point had gone wide 10 minutes into the second half. Use of Hawk-Eye was suspended during the
2013 All-Ireland SHC semi-finals on 18 August due to a human error during a minor (under-18) hurling game between Limerick and Galway. During the minor game, Hawk-Eye ruled a point for Limerick as a miss although the graphic showed the ball passing inside the posts, causing confusion around the stadium – the referee ultimately waved the valid point wide provoking anger from fans, viewers and TV analysts covering the game live. The system was subsequently stood down for the senior game which followed, owing to "an inconsistency in the generation of a graphic". Limerick, who were narrowly defeated after extra-time, announced they would be appealing over Hawk-Eye's costly failure. Hawk-Eye was introduced to a second venue,
Semple Stadium, Thurles, in 2016. There is no TV screen at Semple: instead, an electronic screen displays a green
Tá if a score has been made, and a red
Níl if the shot is wide. It was used at a third venue,
Páirc Uí Chaoimh, Cork, in July 2017, for the All-Ireland SHC quarter-finals between
Clare versus
Tipperary and
Wexford versus
Waterford. Hawk-Eye was at the centre of several contentious decisions during the first half of the first
2022 All-Ireland SFC semi-final between
Derry and
Galway.
This led to its suspension for the second half of that game, the referee being forced to alter the score and, later, Hawk-Eye's suspension for the second All-Ireland SFC semi-final between Dublin and
Kerry. The GAA confirmed on 15 July that Hawk-Eye would return for the
All-Ireland SHC final, following comprehensive testing and a full review of the score detection technology. Hawk-Eye malfunctioned again during the
2023 All-Ireland SFC quarter-final clash between
Armagh and
Monaghan after it returned a "data unavailable" message. The GAA requested an explanation from Hawk-Eye who concluded that the message was a result of operator error. The next day the GAA took the decision to stand down Hawk-Eye once again. No official
Irish-language term exists, although some publications have used the direct translation
Súil an tSeabhaic.
Australian football On 4 July 2013, the Australian Football League announced that they would be testing Hawk Eye technology to be used in the Score Review process. Hawk Eye was used for all matches played at the MCG during Round 15 of the 2013 AFL Season. The AFL also announced that Hawk Eye was only being tested, and would not be used in any Score Reviews during the round.
Badminton BWF introduced Hawk-Eye technology in 2014 after testing other instant review technologies for line call decision in BWF major events. Hawk-Eye's tracking cameras are also used to provide shuttlecock speed and other insight in badminton matches. Hawk-Eye was formally introduced in
2014 India Super Series tournament.
Gridiron football The
National Football League adopted Hawk-Eye for virtual on-field measurements beginning in the
2025 season.
Baseball Hawk-Eye is used to automatically call
balls and strikes (either in conjunction with, or in lieu of, a human
umpire) in professional
baseball leagues in the U.S. and South Korea. In the U.S., the system is scheduled to be implemented in
Major League Baseball (MLB) for the
2026 season, having been previously tested in
Minor League Baseball since 2019. Hawk-Eye has also been used for
instant replay reviews in MLB since the
2014 season. ==Concerns about accuracy==