Having first taken an interest in the game in the era o' />

MELBOURNE - In tennis, as in much of the rest of life, things ain't what they used to be.

Having first taken an interest in the game in the era of Jimmy Connors and John McEnroe, I miss the fiery on-court outbursts. What's a tournament without the odd "You cannot be serious!" to an umpire or "You are a pathetic, fat, ugly loser" to a line judge? Technology does have a way of taking the fun out of things.

The technology in question, which will doubtless play a role in tonight's men's singles final at the Australian Open, is Hawk-Eye. The proprietary computer system, whose apt name derives from that of its English inventor Paul Hawkins, has been a feature of all Grand Slam tennis tournaments since the 2006 US Open.

In the French Open, where the ball leaves its mark on the clay court, the information it provides is used only as an on-screen tool for broadcasters.

The system tracks the ball with 10 cameras and compiles the data into a display of its most statistically likely path: thus it is an electronically inferred version of the truth rather than the actual truth.

Luke Aggas, the director of operations for Hawk-Eye Innovations, says this level of accuracy is far better than the human eye can hope to extract from the blur of a 200km/h serve or a blistering forehand winner. But the tolerance, or margin for error, of 3.6mm, sounds like a lot.

Does this mean that a ball that Hawk-Eye rules as 2mm out, could actually be 1.6mm in?

Technically, yes, but such an error would be way below the threshold of human perception, so nothing is lost and much is gained. Aggas says the system is calibrated before each use against high-speed (2000 frame-per-second) cameras and the average deviation at Melbourne Park is actually 2.2mm (ITF specifications call for a tolerance of 5mm), which you have to admit is pretty damn accurate. Interestingly, the average successful appeal rate is 30 per cent.

Still, Ian Taylor, CEO of Dunedin-based Animation Research Ltd, has misgivings. ARL is Hawk-Eye's only competitor in the umpire-review business - its Virtual Eye system was employed in this summer's Ashes cricket series.

Taylor says the system, familiar to fans of yachting, golf and F1, is best used to "add to viewer understanding of the sport; to help them understand how skilled the proponents are.

"We rejected the idea that we could use technology to track balls and then predict 'exactly' where they would have gone after they had hit something," he wrote on a cricketing blog. "[That] question is one we were not as bullish about as our counterparts at Hawk-Eye," he said. "We have taken the unusual step of stating that at times we did not get enough information to make an informed prediction."

Taylor thinks the umpire should be the sole arbiter of what happens, a point of view Aggas understands but does not agree with.

"Some of the biggest cheers from the crowd can be over the Hawk-Eye challenge," says Aggas. "You don't get a John McEnroe outburst but you don't get somebody losing a championship because of a bad line call you can see on TV."

Taylor is right, of course, when he says that the system is only a taking a "best guess", but it's worth adding that it's much better than any human's best guess.

Plainly the players are getting more comfortable with the idea. Rafael Nadal, the defending champion in the 2007 Dubai Open, lost the quarter-final to unseeded Russian Mikhail Youzhny when both Nadal and the umpire (and even Youzhny) agreed a ball was out that Hawk-Eye had called in.

This week, though, Nadal described the system as "a positive thing for the sport. The crowd enjoys it and I enjoy because you have your chance [to appeal]."

Adds Aggas: "Federer said in his first match with Hawk-Eye that he could not think about anything else. But now they don't have to think about whether they've been screwed over by a call. They put their racquet up and that's that."