Tennis coaches have long used post-match data to help their players improve and understand the strengths and weaknesses of their opponents.
Such statistical analysis is usually a long, drawn-out process involving considerable guesswork — and of little help in the middle of a match.
Belgian tennis coach Wim Fissette recalled looking for patterns in the game play of his charges to pinpoint what areas needed improvement. Working through three or four matches took as much as 10 hours.
"I took a piece of paper and I made dots of where the balls were landing and of course it was not [very accurate]," Fissette, who has coached top players including Kim Clijsters, Simona Halep and Victoria Azarenka, told CNBC at the sidelines of the WTA Finals championship in Singapore.
He recalled a game in 2010 when he coached Clijsters against Azarenka.
Fissette knew, from watching previous games, Azarenka tended to hit her backhand shots wide when she had the advantage on a tie break. "That's what I told Kim," Fissette said.
Clijsters was skeptical; Azarenka served wide and won a point; and another. Clijster's skepticism turned into surprise. "She looked at me. The third time, she was ready and she won the point," he said.
Things have gotten a lot easier for coaches since then. Current technology allows for the collection of vast amounts of data in real time and companies are already creating tools that can carry out instant analysis.
In 2015, German software firm SAP provided real-time data analytics based on information collected from match umpires and ball tracking cameras. Coaches could access the information on WTA-approved devices and bring to their players during coaching breaks.
For example, when Angelique Kerber begins her semi-final match at the WTA Finals in Singapore this weekend, her coach can theoretically show her real-time data on her opponent's strengths and weaknesses.
Tennis has been relatively slow in using technology to boost in-game performances of players.
Traditionalists believe players should be left to fend for themselves during games and current regulations mostly do not allow coaches to offer on-court coaching in between games - at least for the men.
The WTA broke rank in 2008 by introducing on-court coaching, which is allowed once per set. Coaches can bring hand-written notes and official WTA-authorized electronic devices onto the court during breaks.
Fissette, who still reviews match recordings to pick up subtle hints on how a player performs under pressure, reckoned the analytics can help back up a coach's suggestions during the on-court coaching sessions.
The use of analytics to decide on strategy is not confined to just sports.
It is being used in a myriad of other areas such as retailing, governments and other professional services. Research firm IDC estimated in May global revenues for big data and business analytics will grow from about $122 billion in 2015 to more than $187 billion in 2019.
The drawback of the SAP software was that all coaches had the same information, which meant it wasn't enough to guarantee a success. Moreover, Fissette said, some players tended to get confused when given too much information. "It's the quality of the coach to give the player the right information."
Some of the data that coaches see are also available to fans through the WTA Finals mobile app. This includes information on who won the most points on their first serve, which player hit the most aces and who was the best at converting her tie breakers into points.
It's also a way to get more fans involved in the matches, Steve Simon, WTA CEO told CNBC's "The Rundown" on Thursday.
"It's getting them excited, getting them engaged," he said. "So you could really feel like you are part of the strategy and know what's going to happen, and it's very exciting."
In the end, Fissette added, armed with all of the coaching, data analytics and experience, the player must make the final decision on court.