- Sport Business
- Members Log In
Tennis players tend to abide by the old adage that you save your best serves for the ‘big points’. Often, that means starting a service game with a stock serve, saving the big stuff for crucial points at which the game hangs in the balance. Pratt’s supposition is that the first point in a service game absolutely qualifies as a ‘big point’. She is armed with some stats drawn from the men’s game, the ATP. At 0-0, the server has an 86% chance of winning the game. At 15-0, that win chance percentage rises to 93%. But at 0-15 down, it sinks to 74%.
Before sitting down with the Leaders Performance Institute for an interview during Wimbledon fortnight, Pratt makes a note to reach out to SAP, the German software giant that provides bespoke performance analytics to the Women’s Tennis Association (WTA), to find out whether the same win percentage patterns hold true for the women’s game. Her inkling is that they will, and if they do, she’ll look to build that knowledge into a tangible performance edge for the Australian players, and particularly Daria Gavrilova, the promising young Australian she coaches personally.
Pratt has been coaching for the past eight years; she is one of a new breed of trainers to embrace data analytics in tennis and her methods have evolved as the technology itself has advanced. Tennis Australia has had a performance analysis department within its High Performance Unit for the last seven years – a pedigree in performance data that Pratt believes is more or less unmatched in world tennis.
“I use analytics daily,” explains Pratt. “I use it to prepare a player for their match. I look for strengths and weaknesses within the opponent and then set up a plan of play for my player. Now we have SAP analytics in the WTA, it’s real-time, so when they play in a show court you’re able to see those stats real-time and I do use that. After the match I review my player’s stats with my player. If they win, you’re doing it again for the following opponent. I spend 50 per cent of my time with my player on-court, and then 50 per cent of my time looking at vision or crunching the numbers.”
“I spend 50 per cent of my time with my player on-court, and then 50 per cent of my time looking at vision or crunching the numbers.”
Although Pratt and Tennis Australia rely on their own analytics package for the majority of the time, the data, Pratt explains, is not always entirely accurate as it is input manually by a team of data operatives with little tennis experience. The SAP package, therefore, has been transformative. Using a combination of raw data input by umpires on-court, and forensically accurate Hawkeye ball placement data, SAP has also integrated video into its player coaching platform.
Listen to the latest Leaders Performance Podcast on the data revolution in women’s tennis. Stream or download below, or subscribe to the Leaders Performance Podcast on iTunes.
How it works
Jenni Lewis is the Global Sponsorships Technology Lead at SAP. She has spearheaded the introduction of SAP performance technology to the women’s game and has led on its implementation since the WTA signed a wide-ranging sponsorship deal with SAP in 2013. At the start of the deal term, Lewis spent months at a time on the road with the tour, embedded within the infrastructure of the largest women’s sporting entity in the world, consulting with players, coaches, broadcasters and officials alike to find out just how SAP might be able to contribute to the game. The WTA had introduced its on-court coaching rule, allowing coaches to be called on to the field of play at certain breaks to spend time with their charges, in 2009, and that quickly became the area of focus for Lewis and her team. By 2015, SAP were ready to roll out an initial package and the WTA was prepared to adapt its rules, permitting the coaches to bring tablets with them on to the court as a coaching tool.
“With that rule-change,” says Lewis, talking to the Leaders Performance Institute at the Eastbourne tournament in June, “we’ve been able to do real-time for the last 12 months. When the girls call the coaches out to have a conversation, they’re armed with fact.”
The SAP app, designed to be used with a thumb swipe to counteract the sweaty-fingered effects of 45 degree heat standard in some outposts of the WTA tour, is both simple and comprehensive. Intuitive and careful not to present a swamp of information, it focuses on the five key areas that Lewis’s feedback suggested were of most importance to coaches:
“This is where we start out,” explains Lewis, giving the Leaders Performance Institute a glimpse inside the platform. “It’s the standard match stats that would be input by the umpire. A coach can configure it by set basis. It’s a fairly simple screen and it’s colour-coded. This is from Caroline Wozniacki vs Alize Cornet and we can see that Caroline dominated. She won every stat. A coach can drill down further. Instead of seeing that she served three double faults in the first set, and three double faults in the second set, a coach can actually configure the screen to show the score. So you start to see players who have amazing serving stats, but they’re leading double faults, and you ask how that’s possible. It’s because they’re serving them when it doesn’t matter. And this will allow a coach to come out and say, ‘it’s OK – that didn’t matter.’
The other thing that’s super useful is the 30-30 point. What is her first serve on the 30-30 point? That’s a pivotal moment. As a coach you can understand your own player, but you can also switch to the opponent, and keep track of exactly what’s happened out there on court. Caroline Wozniacki has 100% on first serves in at 30-30. And she won 100% of those points.”
“Here, we see where Caroline Wozniacki was serving her first and second serves from a placement point of view. Very rarely will a coach want to see every single ball, so what we built were a series of scenarios.”
“A coach can be sitting courtside and know exactly where Caroline serves on breakpoint. We have just shown a very clear pattern. On the breakpoints that happened in yesterday’s match, she went down the T on both sides. What that means for the opponent, she knows where the ball is coming. If they’d been able to have a conversation, Alize’s coach would have told her yesterday, ‘breakpoint, she’s going down the middle of the court; take that step.’ So as the match is happening, they should be able to adjust strategy.”
“When the rally starts, we start to track forehands and backhands: where is she hitting forehands and backhands from? Do we want to see every ball? Probably not. So we can show where she’s hitting errors from, where she’s hitting winners from, where is she hitting the first ball after the serve? Has she recovered from the serve? Has she attacked the net? Finally, where does she hit the ball to? The coaches loved this, but it only tells part of the story. When she misses, where does she miss? So we added that. We show the out balls as well.”
Also on hand in Eastbourne is Aga Radwanska’s coach Tomasz Wiktorowski. Radwanksa, Poland’s number one player and a serial winner on the WTA, won the season-ending championships in Singapore last year, and Wiktorowski credits SAP data visuals with playing a large role in that win. Ahead of the tournament Witkorowski had been able to use SAP graphics to show Radwanska – rather than just tell her – that she was hitting the ball from too far behind the baseline. She stepped up, got more aggressive, and won the tournament.
“Contact point is key,” agrees Pratt. “The more they can hold the baseline the better. Another key stat is where the second serve lands and how successful players are on their second serve. I felt my player wasn’t targeting their second serve as well as they were capable of, so I was able to show her and say, ‘listen, this is where your second serve is landing. It’s Hawkeye, it’s real.’ The pace of the serve is also important. You have to get it right directionally but you also have to have a minimum pace. I wanted Gavrilova winning more points on the second serve than she was. When she does, she wins matches, and that’s been a big improvement in her game.”
Changing the game
Pratt is happy to admit that she was against the introduction of the on-court coaching rule, and the licensed use of tablet technology, in the initial phases of its introduction. As a player, Pratt believes that one of her chief weapons was her tactical acumen. “I felt that I would have lost my advantage over a lot of other players,” she says. “You obviously work a long time to gain that experience. At the end of the day, now everyone accepts it’s a level playing field. Even if you are one of the most astute players in the game, I still think the ability for someone to look at things objectively from the side is going to be able to influence the student-of-the-game mentality.”
And with that, Pratt begins to compose a quick email on her tablet to Lewis. Those service win percentage stats will be with her imminently.