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Technology powering the 2022 Commonwealth Games: Hawk-Eye

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As Birmingham prepares for this summer’s Commonwealth Games, we look at some of the inventions that have helped change the sporting world. Here we look at the ball tracking system Hawk-Eye used in cricket.

 

After a 24-year absence, cricket will be returning to the Commonwealth Games and the 2022 games will also mark the first time that the women’s game will be featured.

Many sports have been grappling with how to utilise technology to make sport fairer, by aiding the referee or umpire in their judgement. From goal-line technology used in football to Hawk-Eye in tennis and cricket, computer vision systems are having a growing influence in sport.

One of the trickiest decisions a cricket umpire has to make is whether or not to give a “leg before wicket” (lbw). This denotes instances where a batter is struck directly on their leg (or body) by the bowled ball, and the umpire must then make a pressurised decision as to whether the ball would have otherwise hit the stumps.

In 2000, Roke Manor Research filed a patent application for a video-based system, Hawk-Eye, which helped analyse the flight of the ball. The application focused on image-based data, which was used to assess the likely path of the ball had it not hit the batter. Although no doubt an interesting insight for TV viewers, there are significant drawbacks to relying on purely video images which hindered the system from becoming a tool for helping to make umpiring decisions. Namely, the system won’t work if the ball is obscured from the camera and it cannot distinguish between types of impact.

However, Hawk-Eye was updated to include analysis of the sounds of impacts during play, with this improvement patented in 2003. Coupled with the use of video, this enabled a more precise location of the “event” – such as an lbw impact. Microphones are used to detect audio signals which, when correlated with the video images, can be used to determine the distance from the microphone that an event occurred. When many microphones are used at the same time, additional data ensures that the exact location of the event or impact can be given.

The development of Roke Manor Research’s patented system to make use of both video and audio analysis now makes it a vital part of the decision review process at big-stage cricket matches. And the system will definitely be making an impact in Birmingham over the coming weeks as cricket is, once again, played at the Commonwealth Games.

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