Novak Djokovic’s ability to manipulate the tennis ball is one thing; the Serbian has also mastered the art of challenging umpire decisions. Not always does the Hawk-Eye review system support what the naked eye has seen. But the world number 1 has found his calls for a challenge to come out successful more often than not. “We don’t really have a database, but Djokovic is very good at challenges,” says Fares Saudi, Hawk-Eye’s senior systems engineer, almost instantaneously. “Roger Federer isn’t bad either. I’d say he is quite good. But Djokovic is definitely the best one,” he adds.
Meanwhile, Saudi, who is currently a part of the review system team that is on duty at the Chennai Open, claims that 2009 US Open champion Juan Martin del Potro has a bad track record when it comes to making challenges. “Del Potro is quite famous for being quite bad. I think he doesn’t really judge it on if the ball was in or out. I think for him it’s that if he really wants to win that particular point, then just challenge,” he claims.
There is a sense of being the ‘all knowing’ that comes with the job. The three technicians that sit in the booth near the commentary box never have to ponder over if a ball looked like it was in or out. “We know that straight away. We know the distance each ball has travelled before anyone on court,” Saudi mentions.
The technology however, isn’t flawless. International Tennis Federation (ITF) guidelines dictate that the technology must have a margin of error of five millimetres maximum. Now entering its 10th year of being associated with the sport, Hawk-Eye has steadily improved its accuracy. “When it started, the margin of error was around four millimetres. Now it is 3.6 mm. That means that whatever mark we have, the ball could have actually landed 3.6 mm on either side,” he explains.
The margin remains constant between hard courts and grass courts. Clay courts on the other hand, have not yet implemented the use of the system. While hard courts leave a faint mark and grass courts leave none, the clay court surface provide an accurate position of where the ball touched the surface. “On hard courts, the mark is always five to 10 mm further than where the ball actually landed.
But clay courts leave a mark that is quite accurate. Which is why tournaments like the French Open prefer to use traditional methods by having the chair umpire go down to check where the ball landed,” he says. “The only trouble is that there may be confusion on which shot the player has challenged. So maybe they might just decide to have Hawk-Eye to avoid the confusion,” he adds lightly.
Ten cameras on each court fuels the setup, which often bears the brunt of players’ frustration. Time and again the review would call the ball in, or out, by a single millimetre. Saudi too claims to understand the players’ anger. Yet he does assess various reasons for the cause of their irritation. “Sometimes they’re angry because they still lose the point after review. And sometimes what happens is that if the challenge does go their way, the umpire might ask them to replay the point. So we bear the brunt. It’s the nature of the job,” he asserts.
In other sports, the technology is however used to make fairly unsophisticated decisions. In Nascar for example, engineers are allowed to be in the service pit for only a certain duration. “So we use the cameras to determine exactly when they enter and exactly when they leave,” he explains. In cricket, the cameras predict the trajectory of the ball to determine leg-before wicket decisions.
Still, on the tennis court, there is the satisfaction in being the all-knowing. When asked if the technicians feel like an omnipresent body, Saudi simply replies with a smile: “sometimes.”