Novak Djokovic has won 16 Grand Slam tennis titles thanks to a combination of talent, hard work, coaching – and data. 

Strategy coach Craig O'Shannessy has played a central role in Djokovic's embrace of analytics. The Australian native is clad in Italian colours ahead of the afternoon's ATP Finals match between his charge Matteo Berrettini and fifth seed Dominic Thiem, before attentions shift to Djokovic's evening showdown with Swiss ace Roger Federer.

Image credit: Infosys
Image credit: Infosys

O'Shannessy will provide different data to each of the players he's working with today. The analytical, data-hungry Djokovic gets granular insights, whereas Berrettini prefers to receive only the most significant data. The key to O'Shannessy's success is distilling big data into digestible nuggets that can provide help but not distractions.

"Probably the worst thing that I could do is show him the match chronologically – that's not the way to do it in today's game," O'Shannessy explained during a panel discussion at the ATP Finals in the O2 Arena, hosted by digital services firm Infosys.

O'Shannessy analyses the winning percentages of each type of shot in every matchplay situation for both his players and their rivals to find patterns in their play and understand changes over their careers.

He can then divide the court into a series of grids to understand where to hit, stand and move at different points of the game against each individual opponent.

"It's about finding out of 100 points, the 10 or 15 that matter the most, and explaining to [them] that these are the patterns of play that you want to repeat in these upcoming games to win those matches," he said.

When O'Shannessy started work with Djokovic in 2017, he asked the Serbian what form of data would be most helpful. The first request was video analysis.

O'Shannessy's ability to provide this has been helped by a video portal developed by IT vendor Infosys. At the ATP Finals this month, players and coaches have been logging into the portal at the end of matches to slice and dice every second of action into custom playlists of specific in-game situations, from breakpoints to aces.

These video analytics can provide surprising insights, as O'Shannessy experienced during his time coaching American player Rajeev Ram. At their first tournament together, O'Shannessy sat courtside to watch Ram defeat Gregor Dimitrov and Lleyton Hewitt before finally falling to Ryan Harrison.

"I looked at the matches individually and I missed something big," he recalled. "It was only when I bought those three matches together that I saw the opponents had 18 backhand winners and Rajeev only had one. Very unusual – a red flag."

O'Shannessy observed that Ram was struggling to win points when he played backhands across the court. In response, Ram focused on hitting them down the middle of the court.

The change helped Ram leap from number 270 into the top 100.

"We had him at 28 years of age with his singles career almost over, back inside the top hundred, simply by uncovering where he should not hit backhands, which was cross court," O'Shannessy said.

Changing the game

The technology has also transformed the way that tennis matches are officiated. Umpires can use electronic line calling to ensure they've made the right decision and analysis of their performances to find areas in which they can improve.

Ali Nili, a Gold Badge tennis umpire who works with ATP on developing technology for officiating, recalls that when the Hawk-Eye camera review system was first introduced in 2006, a lot of line umpires retired when their errors were exposed.

"Now at least you can be accountable for every call, every overrule," he said. "When I started 21 years ago, if I would make an overrule, I would never know for the rest of my life if I was right or wrong. Neither would the players. "

Players also benefit mentally from the opportunity to challenge the original decision.

"Whether your view was wrong or right, the ability for the player to move on is a really big deal," added O'Shannessy. "Players would hang on to things for a game or a set or even longer sometimes."

Read next: Digital twins of athletes: the next frontier for sports?

This mental component is a growing area of tennis analytics. Former world number one Andre Agassi claimed that he could anticipate where Boris Becker would service based on whether he stuck his tongue out when he served. In the 11 meetings between the two that followed Agassi's discovery, Becker only won one. 

Today, these hunches can be verified through data. Infosys did this to observe how a fault on a first serve would affect a player's choice of second serve.

"It was shining the torch on a facet which has not been shined on at all in the past," said Raghavan Subramanian, platform head of the Infosys Tennis Platform. "There is a tremendous amount of scope and we barely are scratching the surface here."

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