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Gear: The brains behind the ball


Originally published on: 16/12/10 00:00


"The brains behind the ball," by Jamie Renton, featured in the November 2010 issue of tennishead magazine. For more details on how to subscribe, click here.

Rising high above the grounds at Roehampton's Bank of England Sports Centre, just a healthy lob from the National Tennis Centre, lies a domineering red-brick building, with an equally authoritative inhabitant.

Home to the International Tennis Federation, you’d expect something within the operational walls of the world’s governing body of tennis to grasp your attention. But walk a few corridors beyond the magnificent Davis Cup plinth encased behind a wall of spotless glass in the main entrance and you might have wandered into to the headquarters of NASA – or so a quick scan of the immediate surroundings might have you believe.

Space-age machinery clutters the first of three laboratories; a gargantuan wind tunnel dominates a second room on the right, while technicians stroll in the direction of the third with purpose in their every step.

The difference is, the scientific bodies here don’t wear white coats, and no, this isn’t NASA. This is the ITF Technical Centre – the most advanced tennis-specific research facility in the world.

Over a million dollars-worth of equipment examines every technical aspect of tennis you could possibly imagine. Here, the analysis and testing of one of the sports most crucial bits of equipment – the ball – is a key element, as is evident from the smattering of fuzzy yellow spheres littered around the place.

Out of nowhere, an almighty slap on the wall interrupts the initial calm, as if Andy Roddick has just served beyond the speed of sound a mere two metres away. “Don’t worry, it’s just the cannon” says ITF Sports Engineer James Spurr, raising a casual finger in the direction of a curious glass cabinet in the corner.

“That’s the wear rig,” he explains. “We use it to test the durability of balls by firing a ball against a steel plate. We do 20 impacts at 40 metres per second [around 90 mph] to monitor the wear and tear on a ball.”

The ‘wear rig’ is just one of a number of machines the ITF Technical Centre uses to ensure that balls meet the required specifications laid out in the ‘Rules of The Game’.

“We’ve got plenty of advanced technology, but also, some very simple devices,” says Spurr, this time pointing to a brown wooden box, long and thin enough to house a cricket bat, on the opposite side of the room. “You put balls in, they get battered around against the abrasive surface on the inside of the box and it wears down the felt,” he explains. “The test is designed to create the amount of wear that can be expected after nine games of play.”

Nine games is, of course, the standard duration balls are used at competition level before they are changed. Spurr is unsure why, though. “Tradition, I guess,” he shrugs, a word that seems to be a recurring theme in our discussion of the confines of innovation in tennis.
Other equipment – measuring the mass, size, level of deformation, rebound and colour of balls – is used to root out the dud from the acceptable, ensuring that specific standards are met before balls can be approved for tournament play.

“About 95% of balls that come through the door make the cut,” Spurr reveals, but he admits that since manufacturers understandably send in what they know to be the very best of their batch, the ITF conduct additional testing away from the lab. The engineers travel to tournaments all over the world at short notice, particularly Davis Cup ties, to test the balls both being used in tournament play and sold to the public. “Like a mystery shopper,” Spurr adds with a grin.

The ITF Technical Centre isn’t all about quality control; in fact, approving balls for the year ahead is a smidgeon of the work that goes on at the facility. The main focus of their research is to assist the development and evolution of the game.

“Through the research and testing process, we gather information that we can feed back to the manufacturers,” says the 28-year-old. “It’s beneficial to all sides, because we can tell the manufacturers how they can improve their product so that it is a lot more consistent.

“A lot of the work we do is really around what the elite players are doing, but you also have to consider what Joe Public is doing too.”

Technological developments have helped to ensure a more equal playing field at the highest level over the years but, moreover, they have reduced the complexity of tennis for first-timers, allowing anyone to pick up a racket and ball and just hit.

“You ask anybody if football is a difficult game to play, and they’ll say ‘no’. But ask them if it’s a difficult game to play well, then they’ll say ‘yes’,” says Spurr.

“Ask them if tennis is difficult to play, they’ll say ‘yes’ before you’ve even got to the question of playing it well. That was the main problem before. You needed to make it easier for people to just pick up a racket and a ball and play.“

Developments in ball technology across the spectrum took a new turn in the late 1990s and early 2000s, at a time when the serve threatened to dominate the game – a direction that was failing to captivate audiences.

“Manufacturers and tournaments were worried that people weren’t going to tune in to watch tennis on television, and products weren’t going to be seen,” Spurr remembers.

The worry prompted the ITF to introduce a new specification for balls with different characteristics for use on different surfaces, to halt the growing trend of serve-orientated and one-dimensional matches. The existing balls were classified as Type 2, the middle sibling in the new family. Type 3 balls – with a slightly larger diameter – were introduced in 2002 to slow the game down, while harder, faster Type 1 balls also arrived for use on clay surfaces.

Surprisingly, the manufacturers didn’t take to either says Spurr, who admits that their decision to ultimately wait and see how the game developed turned out to be a smart option. “By simply observing how the game has gone, we found that the new ball types are not actually necessary,” he says.

“What we’ve actually found looking at the serve data at Wimbledon, the Australian Open and the US Open in recent years, is that the number of aces is starting to plateau, and actually go down a bit.

“At Roland Garros, it’s still been going up, but obviously serve speed on clay isn’t such an important skill to have as the weight of the surface takes a lot out of the ball.

“We put it down to the fact that the players have learnt to react quicker to return the ball – people like Andy Murray, who can return anything, no matter how fast the ball is served. Aces are always going to be served, of course, but whether it’s through their physicality or some other type of training, players have learnt to get the ball back.”

It’s an experience that has lead Spurr and his colleagues to believe that while testing and ball approval in line with the Rules of the Game remains crucial, advancing ball technology is unnecessary at this moment in time.

“There’s so much tradition in the game that what we end up doing is tailoring the ball-testing process to pass what has already been,” he admits. “But there’s so much potential with the technology here.”

Spurr refers to the wind tunnel in the far room, the intimidating innovation that is used – in this case – to measure the aerodynamic properties of tennis balls.

So advanced is the technology, the wind tunnel can spin the ball in the airflow, meaning that the ITF’s ball-testing methods could even consider the wearing effect of racket-generated spin upon the ball in the near future. They’ve already been measuring the speed of the spin players generate out on the road.

“We’ve measured over 5000 rpm,” Spurr says before breaking into another smile, “basically by following Rafael Nadal around wherever he went.”

With plans to upgrade the in-house wind tunnel to produce spin of between 6-7000 rpm, the testing process aims to stay ahead of the boundaries of human possibility. But as Spurr maintains, the goal is not to make it harder for manufacturers to pass the ball-test, or even force technological enhancements in the game.

“It’s all about improving our understanding at this stage,” he says, but as is evident in the way he delivers his next comment, Spurr is more than a little excited by the possibilities for technological evolution in the game.

“You can test a ball in a 100 different ways,” he considers, “but what’s the point if it’s not relevant to the real world?”


Tim Farthing, Tennishead Editorial Director & Owner, has been a huge tennis fan his whole life. He's a tennis journalist and entrepreneur as well as playing tennis to a national standard. He also helps manage his local club and volunteers for his local tennis organisation. He's a specialist in content about the administration of professional tennis and tennis coaching for all levels.