Serena Williams’ Only Obstacle to a Calendar Slam is Herself

After a 21-minute opening match at the US Open that ended with her opponent’s retirement, Serena Williams is now 6 victories from her first Calendar Slam and 22nd career major title, tying her with Steffi Graf for the woman with the most Slam titles in the Open Era. Williams comes to Flushing Methods with a season match record of 48 wins to 2 losses—a record so close to perfection that you couldn’t blame her if she strutted onto Arthur Ashe and talked trash on a changeover or two (young Aussies, take note). But don’t expect Williams to rock swag until the Open trophy is sitting securely in her hands. As much as the wins keep coming, the queen of the court’s confidence has been in a perplexing slump.

Adversity has been a hallmark of Williams' career. She has had to contend with stereotypes of feminine beauty in a sport that idolizes slender, fair-skinned physiques. She has had to deal with the racism that still exists in a profession dominated by white men. But of all of the crosses she has had to bare none has seemed to cause her as much tried as the pressure of being an elite athlete.

Athletes are so revered and glamorized in our society that we, as fans, sometimes overlook how hard it must be for an elite athlete to stay at the top of his or her game day after day after day. The physical and emotional demands must be immense, especially when added to this is the expectation of flawless excellence, as is the case for Williams' who can send shockwaves through the tennis media for dropping a set.

The burdens of competitive perfection were unusually apparent in Williams' performance at the Western & Southern Open in Cincinnati, her warm-up to the US Open. She looked rattled in matches that should have been a textbook win. The frustration she showed in her semifinal match against 20th ranked Elina Svitolina as she screamed, sighed, and furrowed her brow, was so extreme you might have thought she was the underdog and not the player that would eventually win in straight sets. But her win was ugly, even at times, disquieting. She made 36 unforced errors, had more errors than winners overall, served up 8 double faults, and some serves were so uncharacteristically and poorly executed that the ball floated over the net like a hacky sack. It was as if she was battling something bigger than the present match or even the tournament. In the end, as only a true champion can, she managed to defend her title even though her best game—much like the plot in Season 2 of True Detective—never fully materialized.

This is the puzzle that is Serena Williams.

We may never know the true cause of Williams' crisis of confidence this season (some gratuitous speculation: elbow injury? loss of Sascha? cold feet on the eve of her coronation?) But, with a little number crunching, we might be able to gain some insight about whether—given her immunity to loss—this crisis has had any measurable affect on her game?

Figure 1. Timeline of Serena Williams' Match Wins, 2014 - 2015 (pre US Open)

We can look, for example, at how her performance this season compares to where she was at this stage in 2014 when her self-confidence was more steady. Before the US Open got underway today, Williams had completed 47 matches in 2015 (excluding Fed Cup, retirements and walkovers) and won 45 of those matches (Figure 1). By this point in 2014, Williams had lost 6 matches: a stellar record but still short of her level of dominance this year.

If Williams' win record this season doesn’t justify the ups and downs in her belief, is there another statistic that does? Yes, three-setters.

Figure 2. Timeline of Serena Williams' 3-Set Matches, 2014 - 2015 (pre US Open)

A win by any name is a win, but some come more easily than others. In 2014 by her 47th match, Williams went to 3 sets in 8 matches and won 5 of them (Figure 2). In 2015, she has played 16 three-setters and won all but 1, which means twice as many occasions of being down in a match but winning when her back is against the wall 50% more often than last season. In other words, it isn’t that the ladies’ field has put more pressure on Williams by raising their game rather that Williams is able to win with near certainty even when she isn’t playing her best.

In an interview with ABC, Serena said the following about what she would need to do to win the US Open:

“It’s all up to me. If I decide to play right, it’ll be great.” – Serena Williams

Great, yes. But maybe not necessary.

This year’s US Open will be a real test of Williams' nerves. It isn’t only a chance to win her 22nd major; it’s also a chance to tie Steffi Graf for the most Grand Slam titles won by a woman in the Open Era. As we have seen, Williams is likely to enter the Open with some doubt in her ability despite a phenomenal win record. It is interesting to ask how this contrasts with Graf’s footing going into her final French Open in 1999, where she would ultimately earn her place in the history books.

Figure 3. Timeline of Steffi Graf's Match Wins, 1998 - 1999 (pre French Open)

In terms of wins, Graf entered the French Open with 36 matches and 9 losses, slightly worse than her record of 28-8 after her 36th match in 1998 (Figure 3).

Figure 4. Timeline of Steffi Graf's 3-Set Matches, 1998 - 1999 (pre French Open)

Despite the similarity in her win record in each year, Graf had to fight back from a set down for more of her 1999 wins than she did the year before. By her 36th match in 1998, Graf had played 8 three-setters and won half of them (Figure 4). Going into the French Open in 1999, she had played 15 three-setters and won 10 of them, a dramatic pattern of increasing three-set matches and three-set victories that is stunningly similar to Williams'.

In the pre-Open media swing, when asked about what Williams has to do to prepare for the tournament, Patrick Mouratoglou, Williams' long-time coach said, “She can beat everyone, so it depends on her.” It’s as true a statement for Williams' today as it was for Graf 16 years earlier.

Correction on September 1, 2015: Figure 4 incorrectly repeated Williams' data. The figure now displays Graf’s performance data. Thank you to Adam Gilfix for pointing out this error.