View source for Hawk-Eye

{{short description|Computer vision system}}
{{Other uses|Hawkeye (disambiguation){{!}}Hawkeye}}
{{Use British English|date=February 2013}}
{{Use dmy dates|date=January 2020}}

[[File:Kremlin Cup 2012 - Hawk-Eye cam.JPG|thumb|Hawk-Eye camera system at the [[Kremlin Cup]] tennis tournament on 20 October 2012, Moscow]]

'''Hawk-Eye''' is a [[computer vision]] system used to visually track the trajectory of a ball and display a profile of its statistically most likely path as a moving image.<ref>[https://www.espn.com/sports/tennis/wimbledon08/news/story?id=3452293 Two British scientists call into question Hawk-Eye's accuracy – Tennis – ESPN]. Sports.espn.go.com (19 June 2008). Retrieved on 15 August 2010.</ref> It is used in more than 20 major sports, including [[baseball]], [[cricket]], [[tennis]], [[badminton]], [[hurling]], [[rugby union]], [[soccer]], [[Gaelic football]], [[American football]], and [[volleyball]].<ref name="Boyo">{{Cite web |last=Boyo |first=Sydney |date=2023-09-09 |title=How Sony's Hawk-Eye electronic line-calling system transformed the U.S. Open |url=https://www.cnbc.com/2023/09/09/how-sonys-hawk-eye-works-at-the-us-open.html#:~:text=Since%202022,%20the%20U.S.%20Open,shot%20is%20in%20or%20out. |access-date=2024-09-23 |website=CNBC |language=en}}</ref> 

The [[Sony]]-owned Hawk-Eye system was developed in the United Kingdom by [[Paul Hawkins (mathematician)|Paul Hawkins]]. The system was originally implemented in 2000 for television purposes in cricket.<ref>{{cite news| url = https://www.telegraph.co.uk/sport/cricket/2992943/Hows-that-then-for-hi-tech.html| title = How's that then for hi-tech?| publisher = Telegraph| date = 2000-11-15| access-date = 2022-10-15 | location=London | first=Simon | last=Hughes}}</ref> It works via the use of up to ten high-performance cameras, normally positioned on the underside of the stadium roof, which track the ball from different angles.<ref>{{Cite web |title=Wimbledon Hawk-Eye {{!}} Is it accurate? How it works {{!}} Radio Times |url=https://www.radiotimes.com/tv/sport/tennis/wimbledon-hawk-eye/ |access-date=2024-09-23 |website=www.radiotimes.com |language=en-GB}}</ref> The video from the cameras is then [[Triangulation|triangulated]] and combined to create a three-dimensional representation of the ball's trajectory. Although not infallible, Hawk-Eye is advertised to be accurate to within {{convert|2.6|mm|thou|abbr=on}}.<ref>{{Cite web |title=Hawk-Eye's Accuracy and Reliability |url=https://www.researchgate.net/publication/339921713}}</ref>

Hawk-Eye is increasingly used as an impartial review in sports, having been accepted by governing bodies in tennis, cricket, and association football (soccer) as a means of adjudication. Hawk-Eye has been used for the Challenge System since 2006 in tennis and [[Decision Review System]] in cricket since 2009. The system is also used to determine whether the ball has crossed the goal line in football as a means of [[goal-line technology]], implemented in the [[2013–14 Premier League]] season and now present at many domestic leagues and international competitions.

==Method of operation==
All Hawk-Eye systems are based on the principles of [[Triangulation (computer vision)|triangulation using visual images]] and timing data provided by a number of high-speed video cameras located at different locations and angles around the area of play.<ref name="espacenet"/> For tennis there are 10 cameras. The system rapidly processes the video feeds from the cameras and ball tracker. A data store contains a predefined model of the playing area and includes data on the rules of the game.

In each frame sent from each camera, the system identifies the group of pixels which corresponds to the image of the ball. It then calculates for each frame the position of the ball by comparing its position on at least two of the physically separate cameras at the same instant in time. A succession of frames builds up a record of the path along which the ball has travelled. It also "predicts" the future flight path of the ball and where it will interact with any of the playing area features already programmed into the database. The system can also interpret these interactions to decide infringements of the rules of the game.<ref name="espacenet"/>

The system generates a graphic image of the ball path and playing area, which means that information can be provided to judges, television viewers or coaching staff in near real-time.

The tracking system is combined with a back-end database and archiving capabilities so that it is possible to extract and analyse trends and statistics about individual players, games, ball-to-ball comparisons, etc.

==History==
Hawk-Eye was developed in 2000 by engineers at [[Roke Manor Research Limited]], then a [[Siemens]] subsidiary in [[Romsey]], England. Paul Hawkins and David Sherry submitted a United Kingdom patent application for the technology, but this was subsequently withdrawn.<ref name="espacenet">[https://worldwide.espacenet.com/publicationDetails/biblio?CC=WO&NR=0141884A1&KC=A1&FT=D&ND=3&date=20010614&DB=EPODOC&locale=en_EP VIDEO PROCESSOR SYSTEMS FOR BALL TRACKING IN BALL GAMES] {{Webarchive|url=https://web.archive.org/web/20210309064355/https://worldwide.espacenet.com/publicationDetails/biblio?CC=WO&NR=0141884A1&KC=A1&FT=D&ND=3&date=20010614&DB=EPODOC&locale=en_EP |date=9 March 2021 }} esp@cenet Patent document, 14 June 2001</ref> All of the technology and intellectual property was spun off into a separate company, Hawk-Eye Innovations Ltd, based in [[Winchester, Hampshire]]. This was initially established as a joint venture between Roke Manor Research and [[Tinopolis#Operations|Sunset + Vine]].<ref name=TinoplisInterim2006>{{cite web |title=Tinpolis PLC Interim Results, 14 June 2006 |url=https://www.investegate.co.uk/tinopolis-plc--tin-/rns/interim-results/200606140700435384E/ |access-date=15 October 2022 |archive-date=15 October 2022 |archive-url=https://web.archive.org/web/20221015155904/https://www.investegate.co.uk/tinopolis-plc--tin-/rns/interim-results/200606140700435384E/ |url-status=dead }}</ref> At the time, Sunset + Vine produced the [[Channel 4]] television cricket coverage where Hawk-Eye was first used.

On 14 June 2006 a group of investors—led by the [[Wisden Group]] and that included [[Mark Getty]], a member of the wealthy American family and business dynasty—bought the company for £4.4m.<ref name="TinoplisInterim2006" /><ref>{{cite news |title=Wisden buys Hawk-Eye |url=https://www.theguardian.com/media/2006/jun/14/broadcasting.cricket |access-date=15 October 2022 |work=The Guardian |date=14 June 2006}}</ref> The acquisition was intended to strengthen Wisden's presence in cricket and allow it to enter tennis and other international sports, with Hawk-Eye working on implementing a system for basketball. According to Hawk-Eye's website, the system produces much more data than that shown on television.

Put up for sale in September 2010, it was sold as a complete entity to Japanese electronic giant [[Sony]] in March 2011 in a deal that valued the company at £15m-£20m.<ref name=BBC12670063>{{cite news|url=https://www.bbc.co.uk/news/business-12670063|title=Hawk-Eye ball-tracking firm bought by Sony|publisher=BBC News|date=7 March 2011|access-date=7 March 2011}}</ref><ref name="about">Website company: [http://www.hawkeyeinnovations.co.uk/page/about-hawk-eye About Hawk Eye] {{webarchive|url=https://web.archive.org/web/20130509160917/http://hawkeyeinnovations.co.uk/page/about-hawk-eye |date=9 May 2013 }}, visited 25 May 2012</ref><ref>{{cite news |title=On the ball: Sony pounces on Hawk Eye wizardry |url=https://www.thetimes.com/sunday-times-100-tech/hardware-profile/article/on-the-ball-sony-pounces-on-hawk-eye-wizardry-d6txt7r8xhq |access-date=15 October 2022 |work=The Times |date=6 March 2011}}</ref>

==Deployment in sport==
===Cricket===
{{main|Umpire Decision Review System}}

The technology was first used by [[Channel 4]] during a [[Test cricket|Test match]] between [[England cricket team|England]] and [[Pakistan national cricket team|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 [[Stump (cricket)|stumps]].

In the winter season of 2008/2009 the [[International Cricket Council|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.<ref>{{cite web|url=http://icc-cricket.yahoo.com/about-icc/rules-regulations.html |title=About ICC – Rules and Regulations |publisher=Icc-cricket.yahoo.com |date=1 January 2009 |access-date=1 June 2009 |url-status=dead |archive-url=https://web.archive.org/web/20081226210155/http://icc-cricket.yahoo.com/about-icc/rules-regulations.html |archive-date=26 December 2008 }}</ref>  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.<ref>{{cite web|url=http://www.theroar.com.au/2008/01/24/nine-admits-hawk-eye-not-foolproof/ |title=Nine admits Hawk-Eye not foolproof » The Roar – Your Sports Opinion |publisher=The Roar |date=24 January 2008 |access-date=1 June 2009}}</ref>

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 [[Bowling (cricket)#Line and length|line and length]], or [[Swing bowling|swing]]/turn information. At the end of an [[Over (cricket)|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]]''

[[File:Hawk-Eye at Wimbledon (7508887344).jpg|thumb|Hawk-Eye decision shown on the big screen at Wimbledon.]]
In [[Serena Williams]]'s quarter final loss to [[Jennifer Capriati]] at the [[2004 US Open – Women's singles|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.<ref>[http://www.popularmechanics.com/outdoors/sports/technology/cameras-fouls-and-referees Can Cameras and Software Replace Referees?"] ''Popular Mechanics''. (12 May 2010). Retrieved on 3 September 2010.</ref>

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".{{Citation needed|date=June 2009}} 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.{{Citation needed|date=June 2009}} This was immediately corrected.

Hawk-Eye has been used in television coverage of several major tennis tournaments, including [[The Championships, Wimbledon|Wimbledon]], the [[Queen's Club Championships]], the Australian Open, the [[Davis Cup]] and the [[Tennis Masters Cup]].  The [[US Open (tennis)|US Open Tennis Championship]] announced they would make official use of the technology for the [[2006 US Open (tennis)|2006 US Open]] where each player receives two challenges per set.<ref>[http://www.usopen.org/en_US/news/articles/2006-08-10/200608101155219422122.html] {{webarchive|url=https://web.archive.org/web/20060821194409/http://www.usopen.org/en_US/news/articles/2006-08-10/200608101155219422122.html|date=21 August 2006}}</ref> 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 [[2006 NASDAQ-100 Open|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 [[2006 US Open (tennis)|US Open]] became the first grand-slam tournament to use the system during play, allowing players to challenge line calls.<ref>{{cite news |title=Fish first to use replay in Slam |url=https://news.bbc.co.uk/sport1/hi/tennis/5293942.stm |access-date=14 January 2022 |publisher=BBC Sport |date=28 August 2006}}</ref>

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 {{nowrap|3 mm}}.<ref>{{cite news |author=Barry Wood |url=http://www.nzherald.co.nz/section/4/story.cfm?c_id=4&objectid=10426649 |title=Tennis: Nadal blames line calling system for losing – 02 Mar 2007 – nzherald: Sports news – New Zealand and International Sport news and results |publisher=nzherald |date=2 March 2007 |access-date=1 June 2009 |archive-date=29 September 2007 |archive-url=https://web.archive.org/web/20070929222401/http://www.nzherald.co.nz/section/4/story.cfm?c_id=4&objectid=10426649 |url-status=dead }}</ref> 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.<ref name="Archive.gulfnews.com">{{cite web|url=http://archive.gulfnews.com/indepth/dubaitennis2007/men/10108379.html |title=Gulfnews: Hawk-Eye leaves Nadal and Federer at wits' end |publisher=Archive.gulfnews.com |date=3 March 2007 |access-date=1 June 2009 |url-status=dead |archive-url=https://web.archive.org/web/20090129111245/http://archive.gulfnews.com/indepth/dubaitennis2007/men/10108379.html |archive-date=29 January 2009 }}</ref>

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.<ref>{{cite news| url=http://www.timesonline.co.uk/tol/sport/tennis/article2051307.ece | work=The Times | location=London | title=Hawk-Eye creator defends his system after Federers volley | first=Will | last=Pavia | date=10 July 2007 | access-date=4 May 2010}}{{dead link|date=September 2024|bot=medic}}{{cbignore|bot=medic}}</ref>

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.<ref>{{cite web|url=http://www.thaindian.com/newsportal/sports/berdych-joins-federer-in-anti-hawk-eye-club_100147546.html|title=Berdych joins Federer in anti-Hawk-Eye club|date=27 January 2009|access-date=29 June 2009|archive-date=21 September 2012|archive-url=https://web.archive.org/web/20120921100537/http://www.thaindian.com/newsportal/sports/berdych-joins-federer-in-anti-hawk-eye-club_100147546.html|url-status=dead}}</ref>

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.<ref>{{cite news|url=https://www.theglobeandmail.com/incoming/when-computers-get-it-wrong/article782529/ |title=When computers get it wrong |date=24 March 2009 |access-date=8 July 2012 |work=[[The Globe and Mail]] |location=Toronto}}</ref> 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'''.<ref>{{cite web |date=7 June 2011 |title=Hawkeye and Shot Spot Technology on All Surfaces: The Red Clay Controversy |url=https://bleacherreport.com/articles/725997-hawkeye-and-shot-spot-technology-on-all-surfaces-the-red-clay-controversy |access-date=17 April 2019 |website=bleacherreport.com}}</ref>

The Hawk-Eye Innovations website<ref>{{cite web |url=http://www.hawkeyeinnovations.co.uk/?page_id=1011 |title=Home :: Hawk-Eye |publisher=Hawkeyeinnovations.co.uk |access-date=2 June 2012 |archive-date=31 August 2011 |archive-url=https://web.archive.org/web/20110831091635/http://www.hawkeyeinnovations.co.uk/?page_id=1011 |url-status=dead }}</ref> states that the system performs with an average error of {{nowrap|3.6 mm}}. The standard diameter of a tennis ball is {{nowrap|67 mm}}, 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]].<ref>{{cite web|url=https://www.sportingnews.com/au/tennis/news/australian-open-2021-technology-to-replace-linespeople-at-australian-open/1xtpxbe6cbkku1p3xba29yidg3 |title=Australian Open 2021: Technology to replace linespeople at Australian Open |date=8 February 2021 |publisher=Sporting News |access-date=18 February 2021}}</ref>

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.<ref>{{cite web|url=https://www.essentiallysports.com/why-is-hawk-eye-not-used-at-french-open-2020-atp-wta-tennis-news/ |title= Why is Hawk-Eye Not Used at the French Open 2020? |date= 23 September 2020 |access-date=19 February 2021}}</ref> 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]]).<ref>{{cite web |title=El Mutua Madrid Open contará con la Revisión Electrónica de FOXTENN |url=https://www.madrid-open.com/noticias-mutua/el-mutua-madrid-open-contara-con-la-revision-electronica-de-foxtenn/ |website=Madrid-open.com |access-date=29 May 2021 |location=Madrid |language=es |date=9 February 2021}}</ref> 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.<ref>{{cite news |last=Albarrán |first=Nacho |title=Foxtenn: 40 ojos que suplen las bajadas de los jueces |url=https://as.com/tenis/2021/05/03/masters_1000/1620043372_262867.html |access-date=29 May 2021 |work=AS |date=3 May 2021 |location=Madrid |language=es}}</ref> 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 (tennis)|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.<ref name="tind1">{{cite news|url=https://www.independent.co.uk/sport/tennis/hawkeye-makes-history-thanks-to-rare-british-success-story-at-wimbledon-454677.html|archive-url=https://archive.today/20110818091248/http://www.independent.co.uk/sport/tennis/hawkeye-makes-history-thanks-to-rare-british-success-story-at-wimbledon-454677.html|url-status=dead|archive-date=18 August 2011|title=Hawk-Eye makes history thanks to rare British success story at Wimbledon|work=[[The Independent]]|access-date=3 December 2010|date=23 June 2007|first=Paul|last=Newman|location=London}}</ref> Some tournaments allowed players a greater margin for error, with players allowed an unlimited numbers of challenges over the course of a match.<ref name="tind1"/> In other tournaments players received two or three per set.<ref name="tind1"/> On 19 March 2008, the aforementioned organizing bodies announced a uniform system of rules: three unsuccessful challenges per set, with an additional challenge if the set reaches a tiebreak. In an advantage set (a set with no tiebreak) players are allowed three unsuccessful challenges every 12 games. The next scheduled event on the men and women's tour, the [[2008 Sony Ericsson Open]], was the first event to implement these new, standardized rules.<ref>{{cite news|url=https://news.bbc.co.uk/sport2/hi/tennis/7305404.stm|title=Hawk-Eye challenge rules unified|date=19 March 2008|access-date=22 August 2008 | publisher=BBC News}}</ref>

====Replacement of human line judges====
Since 2021 the Australian Open has used Hawk-Eye to call lines in all games.<ref>{{Cite web |title=Australian Open: In a Grand Slam first, all courts will feature electronic line calling |url=https://www.skysports.com/tennis/news/12110/12207194/australian-open-in-a-grand-slam-first-all-courts-will-feature-electronic-line-calling |access-date=2024-09-23 |website=Sky Sports |language=en}}</ref>  The US Open replaced line judges with full electronic line calls in 2022.<ref name="Boyo" /> On 9 October 2024 the [[All-England Club]] announced that electronic line calling would replace human line judges full-time at Wimbledon starting in [[2025 Wimbledon Championships|2025]].<ref>{{Cite web|url=https://www.theguardian.com/sport/2024/oct/09/tennis-wimbledon-abolishes-line-judges-after-147-years-electronic-line-calling|first=Tumaini|last=Carayol|website=The Guardian|title=You cannot be serious? Wimbledon abolishes line judges after 147 years|date=9 October 2024|accessdate=9 October 2024}}</ref>

===Association football===
{{main|Goal-line technology}}

Hawk-Eye is one of the [[goal-line technology]] (GLT) systems authorised by [[FIFA]]. Hawk-Eye tracks the ball, and informs the [[referee (association football)|referee]] if a ball fully crosses the goal line into the [[Football pitch#Goals|goal]]. The purpose of the system is to eliminate errors in assessing if a [[Scoring in association football|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 (association football)|Laws of the Game]] that made GLT a permanent part of the game,<ref name="March 2012 IFAB/FIFA">{{cite news|last=Conway|first=Richard|title=Goal-line technology edges closer |url=https://www.bbc.co.uk/sport/football/17228500|access-date=3 March 2012|publisher=[[BBC Sport]]|date=15 April 2012}}</ref> 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.

{{Asof|July 2017}}, licensed Hawk-Eye systems were installed at 96 stadiums. By number of installations, Hawk-Eye is the most popular GLT system.<ref>{{cite web|title=Football Technology – RESOURCE HUB|url=https://football-technology.fifa.com/en/resource-hub/certified-product-database/goal-line-technology/installations/|publisher=FIFA|access-date=13 July 2017|archive-url=https://web.archive.org/web/20180617015515/https://football-technology.fifa.com/en/resource-hub/certified-product-database/goal-line-technology/installations/|archive-date=17 June 2018|url-status=dead}}</ref> Hawk-Eye is the system used in the 
[[Premier League]],<ref name="BBC_Premier">{{cite news | url=https://www.bbc.co.uk/sport/football/22107409 | title=Goal-line technology: Premier League votes in favour for 2013-14 | work=BBC | date=11 April 2013 | access-date=11 April 2013}}</ref> [[Serie A]]<ref>{{cite news|title=Serie A approves goal-line technology for next season|url=http://www.espnfc.co.uk/italian-serie-a/story/2297461/serie-a-approves-goal-line-technology-for-next-season|access-date=6 January 2016|work=ESPN FC|date=13 February 2015}}</ref> and [[Bundesliga]]<ref>{{cite web|url=http://www.carlyleobserver.com/sports/bundesliga-approves-hawk-eye-goal-line-technology-for-new-season-1.1650074|title=Bundesliga approves Hawk-Eye goal-line technology for new season|access-date=4 December 2014|archive-date=29 October 2020|archive-url=https://web.archive.org/web/20201029003339/https://www.carlyleobserver.com/sports/bundesliga-approves-hawk-eye-goal-line-technology-for-new-season-1.1650074|url-status=dead}}</ref> among other leagues.

===Snooker===
{{update|snooker|date=December 2014}}
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.<ref>{{cite web|url=https://www.bbc.co.uk/pressoffice/pressreleases/stories/2007/04_april/04/snooker.shtml |title=Press Office – BBC Sport to feature Hawk-eye in World Snooker Championship coverage |publisher=BBC |access-date=1 June 2009}}</ref> 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.{{Citation needed|date=April 2012}} 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 county football team|Dublin]] and [[Down county football team|Down]] and hurling between [[Dublin county hurling team|Dublin]] and [[Kilkenny county hurling team|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.<ref>{{cite news|url=http://www.irishtimes.com/sports/gaa/2011/0324/1224292988742.html |newspaper=[[The Irish Times]] |title=GAA to trial Hawk-Eye at Croke Park |date=24 March 2011 |archive-url=https://archive.today/20120903133158/http://www.irishtimes.com/sports/gaa/2011/0324/1224292988742.html |archive-date= 3 September 2012 |url-status=dead }} Uses in Gaelic football and hurling.</ref>

Hawk-Eye's use was intended to eliminate contentious scores.<ref>{{cite news|url=http://www.rte.ie/sport/gaa/football/2013/0515/392343-gaa-hope-hawkeye-will-stop-contentious-points/|title=GAA hopes Hawk-Eye will eliminate contentious points|work=[[RTÉ Sport]]|date=15 May 2013|access-date=15 May 2013}}</ref> Its first use in the championship came on Saturday 1 June 2013 for the [[Kildare county football team|Kildare]] v [[Offaly county football team|Offaly]] game, part of a double header with a second game of [[Dublin county football team|Dublin]] v [[Westmeath county football team|Westmeath]].<ref>{{cite news|url=http://www.rte.ie/sport/gaa/football/2013/0601/454037-live-saturdays-gaa-championship-action/|title=Live: Saturday's GAA Championship action|work=[[RTÉ Sport]]|date=1 June 2013|access-date=1 June 2013|quote=18:41 – A quick observation on Hawkeye which was used for the first time in the Kildare v Offaly game. It did not delay the game at all and the result came through on our screens within 15 seconds of the referee calling for Hawkeye. The composite picture on television showed clearly that the ball had gone wide. Good start for the new technology.}}</ref> Hawk-Eye determined that Offaly substitute [[Peter Cunningham (Gaelic footballer)|Peter Cunningham]]'s attempted point had gone wide 10 minutes into the second half.<ref>{{cite news|url=http://www.hoganstand.com/ArticleForm.aspx?ID=193535|title=Hawkeye makes successful debut|work=Hogan Stand|date=2 June 2013|access-date=2 June 2013}}</ref>

Use of Hawk-Eye was suspended during the [[2013 All-Ireland Senior Hurling Championship|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.<ref name="rte_error_at_croke_park">{{cite news|url=http://www.rte.ie/sport/gaa/hurling/2013/0819/469099-hawk-eye-admits-to-human-error-at-croke-park/|title=Hawk-Eye admits to human error at Croke Park as Limerick confirm appeal|work=RTÉ Sport|date=19 August 2013|access-date=19 August 2013}}</ref> 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.<ref>{{cite news|url=http://www.independent.ie/sport/hurling/gaas-hawkeye-stood-down-following-error-during-allireland-minor-semifinal-29508303.html|title=GAA's 'Hawkeye' stood down following error during All-Ireland minor semi-final|work=Irish Independent|date=18 August 2013|access-date=18 August 2013}}</ref> The system was subsequently stood down for the senior game which followed, owing to "an inconsistency in the generation of a graphic".<ref>{{cite web|url= https://www.bbc.co.uk/sport/gaelic-games/23766418|title= Limerick to appeal after Hawk-Eye blunder in minor hurling game|date=20 August 2013|work= BBC Sport|access-date=20 August 2013 }}</ref> Limerick, who were narrowly defeated after extra-time, announced they would be appealing over Hawk-Eye's costly failure.<ref name="rte_error_at_croke_park"/> Hawk-Eye apologised for this incident and admitted that it was a result of human error.{{citation needed|date=July 2022}} The incident drew attention from the UK, where Hawk-Eye had made its debut in English football's [[Premier League]] the day before.<ref name=reuters_limerick_hurling_blunder>{{cite news|url=http://uk.reuters.com/article/oukoe-uk-ireland-hawkeye-idUKBRE97I0YE20130819|archive-url=https://web.archive.org/web/20160107033045/http://uk.reuters.com/article/oukoe-uk-ireland-hawkeye-idUKBRE97I0YE20130819|url-status=dead|archive-date=7 January 2016|title=Irish officials suspend Hawk-Eye system after glitch|work=Reuters|date=19 August 2013|access-date=19 August 2013}}</ref>

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.<ref>{{cite web|url=http://www.rte.ie/sport/gaa/2016/0324/777103-semple-stadium-to-use-hawkeye-for-cork-clash/|title=Semple Stadium to use HawkEye for Cork clash|website=[[RTÉ.ie]]|date=24 March 2016}}</ref> It was used at a third venue, [[Páirc Uí Chaoimh]], Cork, in July 2017, for the All-Ireland SHC quarter-finals between [[Clare county hurling team|Clare]] versus [[Tipperary county hurling team|Tipperary]] and [[Wexford county hurling team|Wexford]] versus [[Waterford county hurling team|Waterford]].<ref>{{cite web|title=Hawk-Eye will be used at Páirc Uí Chaoimh|url=https://www.rte.ie/sport/gaa/2017/0711/889348-new-score-detection-system-coming-to/|website=RTÉ|date=11 July 2017}}</ref>

Hawk-Eye was at the centre of several contentious decisions during the first half of the first [[2022 All-Ireland Senior Football Championship|2022 All-Ireland SFC]] semi-final between [[Derry county football team|Derry]] and [[Galway county football team|Galway]]. [[2022 All-Ireland Senior Football Championship#Hawk-Eye malfunction|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 county football team|Kerry]].<ref>{{cite tweet|author=The Sunday Game|user=TheSundayGame|number=1545818536584552448|title=Is there a problem with HawkEye? Shane Walsh's free late in the half was deemed wide by the technology at Croke Park, but the replay would suggest otherwise|date=9 July 2022}}</ref><ref>{{cite news|url=https://www.sportsjoe.ie/gaa/technology-got-wrong-jim-mcguinness-slams-shane-walsh-hawkeye-decision-266769|title='The technology got it wrong' — Jim McGuinness slams Shane Walsh Hawkeye decision|publisher=[[Joe (website)|JOE.ie]]|date=9 July 2022}}</ref><ref>{{cite news|url=https://www.balls.ie/gaa/gaa-more-hawkeye-controversy-after-conor-glass-point-ruled-out-516332|title=More Hawkeye Controversy After Conor Glass Shot Appeared To Go Over|publisher=[[Balls.ie]]|date=11 July 2022}}</ref> The GAA confirmed on 15 July that Hawk-Eye would return for the [[2022 All-Ireland Senior Hurling Championship Final|All-Ireland SHC final]], following comprehensive testing and a full review of the score detection technology.<ref>{{cite news|url=https://www.rte.ie/sport/hurling/2022/0715/1310467-hawkeye-returns-for-the-hurling-final/|title=HawkEye returns for All-Ireland hurling final|publisher=[[RTÉ News and Current Affairs]]|date=15 July 2022|accessdate=15 July 2022}}</ref>

Hawk-Eye malfunctioned again during the [[2023 All-Ireland Senior Football Championship#Quarter-finals 5|2023 All-Ireland SFC quarter-final clash]] between [[Armagh county football team|Armagh]] and [[Monaghan county football team|Monaghan]] after it returned a "data unavailable" message.<ref>{{cite news|url=https://www.balls.ie/gaa/hawkeye-armagh-monaghan-561807|title=Hawkeye Fails Again At A Critical Juncture Of Armagh-Monaghan Quarterfinal|publisher=[[Balls.ie]]|first=Donny|last=Mahoney|date=2 July 2023|accessdate=17 July 2023}}</ref> The GAA requested an explanation from Hawk-Eye who concluded that the message was a result of operator error.<ref>{{cite news|url=https://www.irishexaminer.com/sport/gaa/arid-41174845.html|title=No Hawkeye for Sunday's quarter-finals after 'data unavailable' error|publisher=[[Irish Examiner]]|first=John|last=Fogarty|date=2 July 2023|accessdate=17 July 2023}}</ref> The next day the GAA took the decision to stand down Hawk-Eye once again.<ref>{{cite news|url=https://www.independent.ie/sport/gaelic-games/gaelic-football/gaa-reveals-hawk-eye-unavailable-for-todays-all-ireland-sfc-quarter-finals/a1816420467.html|title=GAA reveals Hawk-Eye unavailable for today's All-Ireland SFC quarter-finals|publisher=[[Irish Independent]]|first=Colm|last=Keys|date=2 July 2023|accessdate=17 July 2023}}</ref>

No official [[Irish-language]] term exists, although some publications have used the direct translation ''Súil an tSeabhaic''.<ref>{{cite web|url=http://www.peig.ie/nuacht-as-gaeilge/a-bhfuil-romhainn-amach-ar-an-ngarrai-glas-agus-lasmuigh-de-as-seo-go-ceann-bliana|title=A bhfuil romhainn amach ar an ngarraí glas agus lasmuigh de as seo go ceann bliana…|access-date=24 July 2016|archive-date=7 December 2017|archive-url=https://web.archive.org/web/20171207002759/http://www.peig.ie/nuacht-as-gaeilge/a-bhfuil-romhainn-amach-ar-an-ngarrai-glas-agus-lasmuigh-de-as-seo-go-ceann-bliana|url-status=dead}}</ref><ref>{{cite web|url=http://limerickgaa.ie/gaeilge-cultur/colun-cartai-cuil/|title=Colun: Cartai Cuil|date=29 September 2014|access-date=24 July 2016|archive-date=3 June 2017|archive-url=https://web.archive.org/web/20170603025841/http://limerickgaa.ie/gaeilge-cultur/colun-cartai-cuil/|url-status=dead}}</ref><ref>{{cite web|url=http://tuairisc.staging.educatedmachine.com/contae-an-chlair-i-lar-an-aonaigh-in-athuair/|archive-url=https://web.archive.org/web/20160809112333/http://tuairisc.staging.educatedmachine.com/contae-an-chlair-i-lar-an-aonaigh-in-athuair/|url-status=dead|archive-date=9 August 2016|title=Contae an Chláir i lár an aonaigh in athuair?}}</ref>

===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.<ref>{{cite web|last1=Alleyne|first1=Gayle|title='Hawk-Eye' to Determine 'In or Out'|url=http://www.bwfbadminton.org/news_item.aspx?id=82725|website=bwfbadminton.org|access-date=23 December 2016|archive-date=23 December 2016|archive-url=https://web.archive.org/web/20161223201639/http://www.bwfbadminton.org/news_item.aspx?id=82725|url-status=dead}}</ref> Hawk-Eye's tracking cameras are also used to provide shuttlecock speed and other insight in badminton matches.<ref>{{cite web|title=Hawk-Eye in Badminton|url=http://www.hawkeyeinnovations.co.uk/sports/badminton|website=hawkeyeinnovations.co.uk|access-date=23 December 2016}}</ref> 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 NFL season|2025 season]].<ref>{{Cite web |date=2025-08-01 |title=No chain, no problem: NFL debuts new virtual measurement system during Hall of Fame Game |url=https://www.cbssports.com/nfl/news/no-chain-no-problem-nfl-debuts-new-virtual-measurement-system-during-hall-of-fame-game/ |access-date=2025-08-01 |website=CBSSports.com |language=en}}</ref><ref>{{Cite news |last=Sullivan |first=Becky |date=2025-04-01 |title=Say goodbye to chain crews: The NFL will use camera technology to measure 1st downs |url=https://www.npr.org/2025/04/01/nx-s1-5347990/nfl-first-downs-measurements-hawk-eye |access-date=2025-08-01 |work=NPR |language=en}}</ref>

=== Baseball ===
{{main|Automated Ball-Strike System}}
Hawk-Eye is used to automatically call [[Strike zone|balls and strikes]] (either in conjunction with, or in lieu of, a human [[Umpire (baseball)|umpire]]) in professional [[baseball]] leagues in the U.S. and South Korea.<ref name=":0">{{Cite web |last=Carroll |first=Shannon |date=2025-09-23 |title=MLB approves robot umpires (ABS) for the 2026 season |url=https://qz.com/mlb-robot-umpires-2026-sony-hawk-eye |access-date=2025-09-24 |website=Quartz |language=en}}</ref><ref>{{Cite web |last=Sato |first=Mia |date=2025-09-23 |title=MLB will use robot umpires beginning next season |url=https://www.theverge.com/news/783982/mlb-baseball-robot-umpires-abs |access-date=2025-09-24 |website=The Verge |language=en-US}}</ref><ref>{{cite news |last1=수현 |first1=최 |title='0.78㎝ 차이' 칼같은 판정… '로봇 심판'이 야구를 바꾼다 |url=https://www.chosun.com/opinion/2024/05/03/HMOTI4H7XNG2ROTADG7IECVO7M/ |access-date=May 3, 2024 |work=조선일보 |lang=korean}}</ref> In the U.S., the system is scheduled to be implemented in [[Major League Baseball|Major League Baseball (MLB)]] for the [[2026 Major League Baseball season|2026 season]], having been previously tested in [[Minor League Baseball]] since 2019.<ref name=":0" /><ref name="mlb-2026">{{cite news |last1=Blum |first1=Ronald |date=2025-09-23 |title=Robot umpires approved for MLB in 2026 as part of challenge system |url=https://apnews.com/article/robot-umpires-mlb-2026-d70c6431d1cccfcf7a6e69e3ce47b417 |access-date=September 23, 2025 |work=[[Associated Press]] |language=en}}</ref> Hawk-Eye has also been used for [[Instant replay in Major League Baseball|instant replay reviews]] in MLB since the [[2014 Major League Baseball season|2014 season]].<ref>{{Cite web |date=2020-07-20 |title=MLB adding 12 new replay angles for ump reviews |url=https://www.espn.com/mlb/story/_/id/29503929/mlb-doubles-camera-angles-video-reviews-umpires |access-date=2025-10-02 |website=ESPN.com |language=en}}</ref><ref>{{Cite web |last=Kurz |first=Phil |date=2020-08-20 |title=MLB Rolls Out Hawk-Eye Next-Gen Baseball Tracking, Analytics Platform |url=https://www.tvtechnology.com/news/mlb-rolls-out-hawk-eye-next-gen-baseball-tracking-analytics-platform |access-date=2025-10-02 |website=TV Tech |language=en}}</ref><ref>{{Cite web |last=Jedlovec |first=Ben |date=2020-07-20 |title=Introducing Statcast 2020: Hawk-Eye and Google Cloud |url=https://technology.mlblogs.com/introducing-statcast-2020-hawk-eye-and-google-cloud-a5f5c20321b8 |access-date=2025-10-02 |website=MLB Technology Blog |language=en |via=[[Medium (website)|Medium]]}}</ref>

==Concerns about accuracy==
Hawk-Eye is now familiar to sport fans around the world for the views it brings into sports like cricket and tennis. Although this new technology has for the most part been embraced, it has received criticism from some quarters. In the [[2007 Wimbledon Championships]] a shot that appeared to be out, was called by Hawk-Eye as in by 1{{nbsp}}mm, a distance smaller than the advertised mean error of {{nowrap|3.6 mm}}.<ref>[https://spectrum.ieee.org/hawkeye-in-the-crosshairs-at-wimbledon-again IEEE Spectrum: Hawk-Eye in the Crosshairs at Wimbledon Again]. Spectrum.ieee.org. Retrieved on 15 August 2010.</ref> Some commentators have criticised the system's {{nowrap|3.6 mm}} statistical margin of error as too large.<ref>[https://www.theguardian.com/sport/2007/jul/11/tennis.wimbledon Big debate: Was Roger Federer right to criticise Hawk-Eye? | Sport]. The Guardian. Retrieved on 15 August 2010.</ref> Others have noted that while {{nowrap|3.6 mm}} is extraordinarily accurate, this margin of error is only for the witnessed trajectory of the ball. In 2008, an article in a peer-reviewed journal<ref>Collins, H. and Evans, R. 2008. "You Cannot Be Serious! Public understanding of technology with special reference to 'Hawk-Eye'". Public Understanding of Science 17:3, {{cite web|url=http://www2.geog.ucl.ac.uk/~mdisney/teaching/1006/papers/collins_hawkeye.pdf |title=Archived copy |access-date=22 August 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111003222351/http://www2.geog.ucl.ac.uk/~mdisney/teaching/1006/papers/collins_hawkeye.pdf |archive-date=3 October 2011 }}</ref> consolidated many of these doubts. The authors acknowledged the value of the system, but noted that it was probably fallible to some extent, and that its failure to depict a margin of error gave a spurious depiction of events. The authors also argued that the probable limits to its accuracy were not acknowledged by players, officials, commentators or spectators. They hypothesised that Hawk-Eye may struggle with predicting the trajectory of a cricket ball after bouncing: the time between a ball bouncing and striking the batsman may be too short to generate the three frames (at least) needed to plot a curve accurately.

==Use in computer games==
The use of the Hawk-Eye brand and simulation has been licensed to [[Codemasters]] for use in the video game ''[[Brian Lara International Cricket 2005]]'' to make the game appear more like television coverage, and subsequently in ''[[Brian Lara International Cricket 2007]]'', ''[[Ashes Cricket 2009]]'' and ''[[International Cricket 2010]]''. A similar version of the system has since been incorporated into the [[Xbox 360]] version of ''[[Smash Court Tennis 3]]'', but it is not present in the [[PlayStation Portable|PSP]] version of the game, although it does feature a normal challenge of the ball which does not use the Hawk-Eye feature. It is also featured (Called Big Eye) in ''[[Don Bradman Cricket 14]]'' and ''[[Don Bradman Cricket 17]]''.

==Competition==
[[Cyclops (computer system)|Cyclops]] is a computer system which has been used on the ATP and WTA professional tennis tours as an electronic line judge since 1980, now superseded by Hawk-Eye at Grand Slam tournaments.

[[FoxTenn]] is another competing system for electronic line judge calling<ref>{{cite news|url=https://scroll.in/field/916856/hawkeye-vs-foxtenn-two-tech-firms-are-battling-it-out-to-win-the-tennis-line-call-business |title=Hawkeye vs FoxTenn: Two tech firms are battling it out to win the tennis line-call business|date=16 March 2019 |access-date=3 October 2020}}</ref> which uses real data to trace back ball path and marking, including on clay surfaces.

==See also==
{{Portal|Cricket}}
* [[Cricket clothing and equipment]]
* [[Electronic line judge]]
* [[Cyclops (computer system)|Cyclops]]
* [[Hot Spot (cricket)]]
* [[Umpire Decision Review System]]
* [[Virtual Eye]]

==References==
{{Reflist|30em}}

==External links==
* [http://www.hawkeyeinnovations.co.uk/ Hawk-Eye Innovations] {{Webarchive|url=https://web.archive.org/web/20110629034124/http://www.hawkeyeinnovations.co.uk/ |date=29 June 2011 }}
* [https://web.archive.org/web/20120217174455/http://video.google.co.uk/videoplay?docid=3469862161470408694&hl=en-GB A video demonstration of Hawk-eye at a cricket match]
* [http://www.howitworksdaily.com/technology/top-five-facts-controversial-hawk-eye-moments/ How It Works magazine – Controversial Hawk-Eye moments]

{{Cricket equipment}}
{{tennis box}}

[[Category:English inventions]]
[[Category:Companies based in Hampshire]]
[[Category:Cricket equipment]]
[[Category:Cricket terminology]]
[[Category:Gaelic games terminology]]
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[[Category:Sports officiating technology]]
[[Category:Tennis equipment]]
[[Category:Tennis terminology]]