Hawk-Eye is a computer system used in cricket, tennis and other sports to visually track the path of the ball and display a record of its most statistically likely path as a moving image [1]](Hawk-Eye - Wikipedia). In some sports, like tennis, it is now part of the adjudication process. It is also used in some instances to predict the future path of a ball in cricket. It was developed by engineers at Roke Manor Research Limited of Romsey, Hampshire in the UK, in 2001. A UK patent was submitted by Dr Paul Hawkins and David Sherry.[2]](Hawk-Eye - Wikipedia) Later, the technology was spun off into a separate company, Hawk-Eye Innovations Ltd., as a joint venture with television production company Sunset + Vine.
Method of operation
All Hawk-Eye systems are based on the principles of triangulation using the visual images and timing data provided by at least four high-speed video cameras located at different locations and angles around the area of play.[2]](Hawk-Eye - Wikipedia) The system rapidly processes the video feeds by a high speed video processor 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 3D 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 traveled. 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. [2]](Hawk-Eye - Wikipedia)
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 pure tracking system is combined with a backend database and archiving capabilities so that it is possible to extract and analyse trends and statistics about individual players, games or ball to ball comparisons etc.
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 however, this is disputed by Michael Pattison who firmly believes it was first introduced by Sky.citation needed] It is used primarily by the majority of television networks to track the trajectory of balls in flight. In the winter season of 2008/2009 the ICC trialled a referral system where Hawkeye was used for referring decisions to the third umpire if a team disagreed with an LBW decision. 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.[3]](Hawk-Eye - Wikipedia)
Its major use in cricket broadcasting is in analysing leg before wicket 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 wicket. Consultation of the third umpire, for conventional slow motion or Hawk-Eye, on leg before wicket decisions, is not currently sanctioned in international cricket and doubts remain about its accuracy in cricket.[4]](Hawk-Eye - Wikipedia)
Due to its realtime coverage of bowling speed, the systems are also used to show delivery patterns of 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 show 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 batsmen scored from. These are often shown as a 2-D silhouetted figure of a batter 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.
Doubts
Hawkeye is now known around the world for the amazing results and views it brings into sports like cricket and tennis. Although this new technology seems quite amazing with its results, it has been recently criticised by the Australian media for a specific LBW appeal made by Anil Kumble when Andrew Symonds was batting. The ball, as suggested by Hawkeye, would have bounced over the stumps, but to the naked eye looked absolutely out. At this point in time Hawkeye was doubted and still is although it seems likely Hawkeye will continue to be used throughout sports such as cricket, tennis and snooker. [12]](Hawk-Eye - Wikipedia)
The BBC continued to use the system sporadically, for instance in the 2009 Masters from Wembley Hawkeye was used once or twice per frame, at most. It was generally used to switch seamlessly from matching a live camera view then swinging the virtual camera to examine a tricky shot from the player’s viewpoint.
http://resources2.news.com.au/images/2009/11/26/1225804/375346-dtstory-ricky-ponting.jpg](http://resources2.news.com.au/images...ky-ponting.jpg)
I think Hawkeye is not very good at judging the bounce of the ball. It does predict line accurately though IMO
