Decision Review System September 1, 2011

'ICC could monitor ball-tracking technologies'

An independent software funded and developed by the ICC would help evaluate the accuracy of the two competing ball-tracking technologies, Paul Hawkins, the Hawk-Eye chief executive, has said. The two ball-tracking technology providers for cricket are Hawk-Eye, used for the 2011 World Cup among other series, and Virtual Eye, used during the 2010-11 Ashes.

Hawkins said that though an independent software may not be as accurate as the two systems currently in use, it would still be good enough to point out glaring errors committed by either technology provider. He also suggested penalties be imposed on either provider if they were found to be consistently inaccurate.

"What we have proposed to the ICC, which I feel will be hugely beneficial to everyone involved, including ourselves, is a software solution which the ICC could use to independently monitor both systems, ourselves and Virtual Eye," Hawkins told ESPNcricinfo. "So any lbw decision used for DRS, or not for DRS, that anyone has concern with, be it the board, players or the umpires, then the ICC can look into it in the same way that they evaluate the human umpires. It'll be very easy for them to have a software that will give them independent answers for pitch point, interception point, prediction of whether the ball will go on to hit the stumps.

"It certainly won't be as accurate as our system but will be accurate enough to highlight if either system had made a glaring error, of over two centimetres for example. Since it will be developed by the ICC, who have the best interests of the game at heart, they can independently produce track records of both systems and we would be happy to hold our hands up and say, 'If we make too many glaring errors, then we should lose our license to be able to provide ball-tracking systems,' and that would have to apply to Virtual Eye as well."

Such a system, Hawkins said, would help in a couple of ways: "That's a quality-control mechanism that would give everyone the trust. And from a technology person's perspective, it keeps us on our toes because we'll know that there is a downside to us not providing accurately reliable technology."

While ball-tracking continues to be used in cricket coverage, it has been made optional in the Decision Review System (DRS), largely due to opposition from the BCCI, which has questioned its accuracy and said it isn't fool-proof.

The software would have to be developed by a neutral body approached by the ICC, but Hawkins said generating such a system was not difficult "It doesn't require a lot of expertise," he said. "It can be developed in a week. To do the scaled-down model that doesn't need to work in real time, it can have human input and can be developed easily.

"Let's just say it's got to decide whether the distance between pitching and hitting the batsman is accurate to within 1 cm, and the prediction of whether the ball's going to hit the stumps accurate to within 2.5 cms. For every decision, it can give a tick or a cross. They [ICC] are at the stage of working out how best to go about it. My hope is that an independent body does become established so that both companies can promote their own track records and it'll be very definitive."

One of the significant disagreements between Hawk-Eye and Virtual Eye is over frame-rates of the cameras used in ball-tracking, and the role they play in determining an accurate track. Hawk-Eye's cameras track the ball at 106 frames per second, and Virtual Eye, during the Ashes in 2010-11, tracked it at 230. In an interview on ESPNcricinfo's audio show Time Out, Ian Taylor, chief of Virtual Eye, said the higher the frame-rate, the better the decisions can be due to more data being available for establishing a ball-track. Hawkins, however, challenged that claim.

"It's completely misleading, in fact it's wrong," Hawkins said. "If it was just about frame-rates, why not have cameras of 1000 frames per second, or 2000 frames per second. You can get cameras that run for 10,000 frames per second. We have run a higher frame-rate system alongside our lower frame-rate system and our lower frame-rate system has worked better, just to explain to you how important frame-rates are in the overall scheme of things.

"You need very high-resolution cameras in order to accurately find the centre of the ball in each image. You need very accurate calibration mechanisms to know exactly what the calibration or the lens distortions of the cameras are, you need to be able to very accurately synchronise your cameras so that an image taken from one camera is taken at exactly the same time as an image taken from another camera. Or you need to compensate for that by knowing the time difference between the cameras. And you need to be able to compensate for any wobble there might be in the camera."

Ball-tracking technology for DRS is currently in use for Australia's tour of Sri Lanka.

Siddhartha Talya is a sub editor at ESPNcricinfo

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