Measuring Ball Speed in Cricket

To pick the speed of a ball requires calibration. Hawk-Eye uses six cameras to track the ball.

A feature of modern televised cricket that we take for granted is the speed of each ball delivered by the bowler. It is displayed barely for two seconds after every burst of action, but it serves its purpose and disappears into wherever cricketing numbers go. Our trust in these numbers, like with other cricket stats, is implicit. But the technology to register ball speeds in cricket isn’t perfect.

Visitors to Cricinfo’s commentary sessions for the first few games of the World Twenty20 tournament were bemused by bowler speeds. In five consecutive balls to Pakistan’s Salman Butt, Dirk Nannes, the Australian fast bowler, could muster speeds no greater than 110 kph. In comparison, South Africa’s bowlers went past 160 kph more than once. Cricinfo’s live updates had this gem: ‘Raina comes down the pitch, Morkel sends down a slower one (158.9 kph) and Raina makes room and pushes it wide of cover.’

Cricinfo’s commentators told readers to excuse the numbers, and then expunged them from its archives. Hawk-Eye, the ball-tracking technology that is sometimes spoken of as a serious aid to cricket umpires, fed Cricinfo numbers that defied belief.

In an email on Tuesday, Paul Hawkins, director of Hawk-Eye Innovations, explains, ‘We had all sorts of freight problems with getting kit to the West Indies largely due to the volcanic ash, so the start of the event has had some technical problems, since we are using kit we have never used before. Things are stable now.’

To pick the speed of a ball requires calibration. Hawk-Eye uses six cameras that track the ball out of the bowler’s hand until it is no longer in play. The position of the ball is recorded numerous times each second. Any errors are tended to immediately. But it hasn’t stopped participants from pointing out the technology’s flaws.

So is there anything better? Not really. The alternative, the speed gun, throws up varied readings. Even numbers on hand-held speed guns vary. Geoff Lawson, a former Australian fast bowler, claimed that speeds depend on whose radar is being used for the game. The last word goes to a former producer, who writes that Hawk-Eye ‘can be manipulated, as can the others, and it does not offer an improvement to the umpires’ judgement, unlike Snicko and Hot Spot which have real value.’

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