Porcupyn's Blog

February 12, 2010

The Hawk-Eye

Filed under: Sports,Tennis — Porcupyn @ 7:58 am

You are watching a World Cup Football match and watch an egregious foul being committed away from the ball. The referee and linesman are too far away to see the action away from the action. Suddenly, the referee gets a call into his earpiece, he stops the action, and red cards the offender.

Don’t think it could happen? Think again – Hawk-Eye, the revolutionary company that has brought current technology into modern sports, is getting into Football. After addressing obvious issues such as ensuring whether or not the ball crossed the goal-line, players elbowing the ball into the goal etc, I hope the technology goes into the uncharted territory of ensuring that would-be Beckers dive on the Tennis court, not on the Football field, and in Zidane-type of incidents, both players are cautioned (I guess Zidane would still get the red card).

That said, it is ironic that I still have issues with the hawk-eye technology in Tennis but not in Cricket. Ironic because in Cricket, a good portion of the debatable decisions (the famous LBW) are where technology tracks where the ball might have gone contentious issues occur when the technology tracks where the ball has already been! Here is my major peeve with Tennis calls:

This post does a very good job of explaining the multiple angles that Hawk-Eye apparently uses to determine where exactly a Tennis ball landed. However, I remain unconvinced. Let me rephrase that – my issue is with the marginal calls that Hawk-Eye judges to be on the line.

When you take a photo of the ball from arguably the best possible angle, i.e. from right above it, what you see is the part of the court that is eclipsed by the ball. Then you get into the science of determining what part of the ball actually touches the ground (only the part of the ball touching the ground technically counts in determining whether the ball is in or out).

There are probably two good ways for Hawk-Eye to be calibrated.

– paint the balls and compare the marks with the camera’s ruling as to whether the ball was in or out (precise speed of ball, pressure exerted by it against the ground upon impact etc will need to be measured and considered).

The drawback of this method is that the paint on the balls might dry quickly, comparing the marks against the camera would be time-consuming, will need to ensure that the ball lands cloes to the lines else precise micro-measurements would be difficult etc

– calibrate on (red) clay where impact craters and skid marks are evident. But even there, the degree to which the ball sinks into the clay might not be uniform.

In all this, don’t forget that the difference we are talking is a Nadal Unit* or two
For Hawk-eye to be irrefutably correct, I think one of the following needs to happen – and until that point, one of the players would have grounds to feel peeved:

– the player hitting the ball should have killed it with such force that it literally compressed to a hemiphere

– Hawk-Eye has a camera on the ground-level which can see under the ball to determine whether or not there was a gap between the ball and the sideline.

– it is a no-brainer, as in there is plenty of space between ball and sideline (in or out).

Unfortunately, unlike in Cricket, Tennis has no clear-cut definition – that I am aware of – of giving the benefit of the doubt to either player.

Nadal Unit (previously incorrectly termed Nadal-width by yours truly) = unit of measurement smaller than an Angstrom Unit

[wrote the above when the Australian Open was on; was thinking of modifying something, but now forget what. oh well … here it goes]

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