Melbourne - Rafael Nadal's new high-tech tennis racket looks and feels like his old one. Except for the on-off switch.
Call it a "smart racket," the latest advance in tennis technology tells you where you hit the ball - with the help of an app.
Sensors embedded in the handle of the racket, made by Babolat, record technical data on every ball struck. At the end of a match or training session the data can be downloaded to a smart phone or computer and used to help analyse a player's strengths and mistakes.
Aside from the sensors, the racket is just a racket. It's the same size and weight as Nadal's old-fashioned former racket.
"I know to play well I need to play 70% of forehands and 30% of backhands," Nadal said after racing through his first-round Australian Open match over Mikhail Youzhny on Monday.
"If I'm not doing that, I know I'm not doing the right thing on court."
"This (racket) is a way you can check these kinds of things," added the 14-time Grand Slam winner, who was sidelined for much of last season from a wrist injury and an appendix operation.
The International Tennis Federation had previously outlawed what it calls "player analysis technology" during competition but adopted a new rule in January last year that allows players to wear or use "smart" equipment, like Nadal's new racket and devices like heart-rate monitors that record data about player performance in real time.
Babolat initially fitted the technology into its "Pure Drive" rackets, which are used by Karolina Pliskova, Julia Goerges and Yanina Wickmayer and then incorporated the sensors into a newly-released version of the "AeroPro Drive" racket used by Nadal, Caroline Wozniacki and Jo-Wilfried Tsonga.
Don't expect to see players on their iPhones analysing their game mid-match. An ITF ban on coaching during matches prevents players from consulting the data on court.
The way it works is simple, says company spokesperson Thomas Otton.
There are two buttons on the bottom of the racket's handle.
"You press the 'on' button. A blue LED light appears. And, you play," Otton said. When finished, a second button is pressed, activating Bluetooth which synchronises the information with a smart phone or other device.At a demonstration of the racket before the tournament started, Wozniacki and Nadal joked about the pros and cons of knowing too much.
"Sometimes it's not a good thing," said Wozniacki. "Because you think you're hitting it in the middle of the racket, but really it shows you you're not. And there's no going around that."
Nadal's uncle and coach, Toni, joked that the racket would give him an edge.
"Sometimes when I correct Rafa on how he's hitting the ball, he doesn't agree." said Toni. "Now I have the data."
Nadal retorted, without missing a beat, "Now he has the data to know that he was wrong."