How Easily Can Sharapova Return to the Top of the Game?

14 Apr 2017

With less than 2 weeks until Maria Sharapova makes her return, there is a growing stir of speculation over her comeback. Having already been granted controversial wild cards and 3 Premier events, including the upcoming Stuttgart Grand Prix, Sharapova—after 15 months out of the game—will return to tennis with a unique opportunity to avoid the usual entry prohibitions of unranked players. Her first match will be in the middle of the first round of Stuttgart on April 26th where she will have a chance to take 470 ranking points.

Many players have questioned the fairness of issuing wild cards to a player returning from a ban after such a long period out of the game. Fair or not, the wild cards Sharapova has received make an implicit assumption that she will be able to compete at a high level after being away for 8% the length of her pro career.

But is this assumption reasonable?

Sharapova’s Expected Strength

Although official player rankings are often used to assess a player’s current competitive level, rankings penalize players who do not compete during a 52 week period. This makes rankings little help when assessing the strength of players returning from an absence of play whether due to injury, suspension or other circumstances. With more than a year away from the sport, Sharapova is currently unranked.

Elo ratings—an alternative system for ranking player strength—accumulate as players compete and remain fixed when they do not. Thus, a player’s current Elo rating reflects whatever their ability was at the end of their last match. In many cases, that rating can be a useful proxy for a player’s future competitive level if the time span from their last match is reasonably short and their physical fitness has not changed in the intervening period.

At the end of Sharapova’s loss to Serena Williams in the quarterfinal of the 2016 Australian Open, her last match before her suspension, her Elo rating (based on the system used by the Game Insight Group at Tennis Australia) was 2,392.

If Sharapova is able to play to her level at that start of 2016, where would that put her win expectations against the current top 20 players who have been competitive in 2017? Based on the Elo ratings of the best female players at the end of the first quarter of 2017, Sharapova would be expected to have a strong edge over most. For all but the top 7 players, from Madison Keys down, Sharapova’s match win expectation would be over 75%. Among the top 7, her chances are more than 65% for all but two players: Johanna Konta and Serena Williams. And Serena Williams is the only current player with a higher ranking and, consequently, the only opponent Sharapova would have a less then 50% expected chance of defeating.

Taken at face value, Elo gives a very positive outlook for Sharapova. Add on top of that the uncertainty about the events Serena Williams is going to play during the clay court season, Sharapova would appear to have a clear path back to the top of the game.

But this outlook is based on one fundamental (and potentially flawed) assumption: that Sharapova can pick up where she left off. There are a few reasons we might be skeptical about that view. First, we might wonder whether the depth of the tour has increased during the time Sharapova has been away? If so, even though she might be expected to be the heavy favorite in most matches, she could also expect more of her matches to be close and that could be wearing over multiple events.

State of Tour Depth

To assess trends in depth, we can look at the range in Elo ratings among the top 100 female players at the time Sharapova’s suspension began in 2016 compared to now. A period of high depth would be one in which the top 100 were within a narrow range in ratings, as this would mean that fewer points distinguished the No. 1 and No. 100. When we look between these periods below, we find that the depth on the tour has increased but only slightly, narrowing by 30 Elo points overall. The same is true among the top 30, although the difference is somewhat greater with 40 fewer points differentiating the best player and the 30th best player today than at the start of 2016.

So the depth of the tour hasn’t changed dramatically enough that it would be expected to influence Sharapova’s comeback. Yet, even with the same caliber of opponent, Sharapova might face more of a challenge if the mix of opponents at the highest level are very different than when she was last active.

A New Field of Opponents?

If we look at the trajectories for the current top 50 players, we find that the majority have risen in the Elo standings compared to the start of 2016. Overall, 62% of current top 50 players have a better Elo rating today than at the start of 2016 and the median gain in the Elo rankings has been 26 positions. Of the current top 50, 30% were outside of the top 50 in 2016.

Among the top 10, in fact, three were ranked 20th or below at the time of Sharapova’s suspension: Johanna Konta, Svetlana Kuznetsova, and Elina Svitolina. The new mix of opponents at the top tells us that the players Sharapova is likely to run into in later stages of events where the most ranking points are up for grabs will be a mix of players she has less experience against, which could make for harder matches than her opponents’ ratings would suggest. Opponent mix can’t be ignored when considering Sharapova’s chances of a strong return.

Elo Consistency Over Time

Changes in depth and opponent mix are two factors that could put the accuracy of a post-ban Elo rating into question. But is there more direct evidence that Elo ratings after a gap are any worse than prior to a gap? One way we could consider this is by looking at the correlation between Elo ratings at the start and end of a 15-month period—the length of Sharapova’s ban—for players similar to Sharapova. Now, one could argue that no player has really ever been like Sharapova. But, for this exercise, the key thing is to control for quality and age, two factors that we can expect to have a major influence on a player’s consistency over long periods.

In the women’s game, top 10 players have historically had Elo ratings of 2200 or higher. We therefore look for players who had a rating this high between the ages of 27 and 29. Since 1990, there were 22 players that met this criteria, including Sharapova. We can look at the consistency of Elo ratings for this group at this time in their career over a 15-month period by looking at the change in ratings from the start and end of this period. The scatter plot below shows a strong agreement (correlation of 0.9) in ratings over this time period for this top group of players. The median change among the group was 10 Elo points, a negligible change for players of this caliber.

One of the few players to deviate from the consistency in Elo ratings enjoyed by most at the top of the game was Amelie Mauresmo who followed an excellent 2006 season at age 27, during which she won titles at the Australian Open and US Open, with a disappointing 2007, where she struggled to reach the second week of the major events. An accumulating series of injuries made Mauresmo an exception to the usual pattern.

The general pattern we observe in ratings suggests that top players in their late twenties generally maintain their Elo rating over periods as long as 1 and 1/2 years. Still, regular competitive play could help to maintain that competitive level. That leaves a big question mark as to the importance of match experience for the long-term accuracy of a player’s Elo rating.

Elo Trends Post Suspension

Are there any players who have gone through a suspension that could provide some clue as to a ban’s direct effect on player ability? There are nine female players who have been openly suspended for a doping violation. Only 3 of the suspensions were of a year’s length or more and only one of the players was of the same quality as Sharapova. The latter is Martina Hingis who was banned from playing in late 2007 and subsequently retired from singles competition.

Player	Highest Singles Rank	Ban Start	Ban End
Kristina Antoniychuk	172	May 2010	April 2011
Nuria Llagostera Vives	35	Sep 2015	Retired
Lourdes Domínguez Lino	40	Aug 2002	Nov 2002
Martina Hingis	1	Nov 2007	Retired (Singles)
Barbora Záhlavová-Strýcová	16	Oct 2012	Apr 2013 (Stuttgart)
Sesil Radoslavova Karatantcheva	35	Jan 2006	Jan 2008
Kateryna Ihorivna Kozlova	92	Feb 2015	Aug 2015
Yanina Wickmayer	12	Nov 2009	Dec 2009
Laura Pous Tió	72	Sep 2007	May 2009

For all of the players that returned to the tour, the pattern in their pre and post Elo ratings suggest that most either maintained or increased their rankings in the 12 months during their comeback. This is true even for players returning from the longest suspensions, Laura Pous Tió and Sesil Karatantcheva, who each were banned from competition for more than a year.

In some ways, Barbora Strycova’s comeback from a ban is one of the most interesting to consider in the context of Sharapova’s return as it points out some of the sharp contrasts between what Sharapova’s post-ban experience is likely to be like compared to the experience of other, less popular players. Like Sharapova, Strycova also made her return at Stuttgart. But even though her ban had only been for a 6 month period, she was not given a wild card and so her best shot at the main draw was to go through qualifying. The same was true for her first post-ban Grand Slam appearance at the 2013 French Open. Strycova could only get entry through qualifying making the prospects of reaching the second week at Roland Garros that much harder. No wonder many WTA players feel slighted by top tournaments giving Sharapova a free pass into their main draws.

All together, these analyses don’t provide any strong reason to doubt Sharapova’s ability to return and for the ability of her current Elo ratings to be a fairly accurate indicator of her strength when she makes her first comeback appearance at Stuttgart later this month. Of course, Sharapova will be under greater scrutiny than probably any other female player who has returned from a ban, which could be a counter to the advantages of her wild cards. How she will cope and what her motivation will be are two of the hardest questions to peg down. Her recent comments at the ANA Inspiring Women in Sports conference suggest a confusing mix of determination to make a strong return while also coming to the belief “that life can be OK without tennis”.

In the past, Sharapova has set herself apart by being one of the most doggedly tenacious and business-like in her approach to the game. You could easily imagine a career at the head of boardrooms when she quits tennis for good and it sounds like she has already prepared that path during her time off with internships at Nike and shadowing the NBA commissioner Adam Silver. A large part of her time out of tennis has been playing out what a life after tennis could be, and whether those experiences will help or harm her motivation when she is back on the court is unclear.

If you liked this story, share it with your followers or follow this site @StatsOnTheT on Twitter.