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Despite Serena Williams’ utter dominance over the last two decades, women’s tennis has actually been much more competitive than the men’s game of late, with 20 different Slam champions over the last decade, compared to eight for the men. And in no Slam is that contrast more apparent than the French Open, which offers a sure bet on one side and a crapshoot on the other. While Rafael Nadal has won 13 of the last 16 titles at Roland Garros, there has not been a single female repeat champion at the French since 2008. Despite the uncertainty in the women’s draw, we attempted to predict a winner, simulating the tournament to find estimated probabilities for every single player in the draw to not only reach any given round but also to win it all.
Trying to predict outcomes with probabilities is common in sports. But it is much easier to do in a single game between two teams or even your standard 16-team playoff bracket than it is for a Grand Slam tennis tournament with a draw size of 128. This is because a lot of the probabilities are interdependent and can change meaningfully with each result, particularly unexpected ones. For example, if Naomi Osaka were to lose in an earlier round in the draw, Serena’s probability of winning the French would go drastically up since she would no longer have to play Osaka (against whom she is 2-3 in her career).
Nevertheless, we can still try to predict the outcome of the French Open through a simulation. For my simulation, I used Tennis Abstract’s Elo ratings, which can be adjusted for different surfaces. For instance, Osaka is the second best player overall by Elo (behind Ashleigh Barty), but when just looking at clay, Osaka drops to 11th due to her struggling performance on that surface. Now with the actual draw, we can simulate the tournament thousands of times using Elo ratings to see the different potential outcomes. This will ultimately give us a probability of each player making a certain round or even winning. For instance, if Serena wins the simulation 1,000 out of 10,000 times, she has an approximately 10% chance of winning. While there is seeding in tennis (No. 1-No. 32) the draw is more random than in other professional playoffs, which rely purely on seeding. In a Grand Slam, a No. 1 seed could play a No. 17 seed in the third round or a No. 32 seed. This creates many interesting matchups throughout the tournament with potential upset opportunities to the star players.
Ashleigh Barty: The current women’s No. 1 has been dominant on the tour, recently winning the Miami Open, reaching the finals of Madrid, and quartering at the Italian Open. However, she hasn’t fared as well in Grand Slams historically. She only has one Grand Slam title to her name (the 2019 French Open) and pulled out of last year’s U.S. Open and French, citing concerns over COVID-19. Her game is crafty, so she could be well-suited for the clay despite it being her weakest surface (69% career winning percentage, compared to 72% and 76% for hard and grass). She is also the highest ranked player by clay Elo and has the highest probability to win at 21%. Despite being the favorite to win at Roland Garros, there are some concerns as Barty pulled out of the Italian Open quarterfinals against Coco Gauff with an arm injury. Barty did get an injury break to go her way as the current No. 3 ranked player and clay-court specialist Simona Halep pulled out of the French with a calf injury.
Naomi Osaka: The Japanese-American fan favorite, Osaka enters Roland Garros as the No. 2 seed but with seventh-ranked probability to win the French at 4%. Similar to her male counterpart, No. 2 seed Daniil Medvedev, she is the highest ranked player in her half but is not the favorite to emerge from her section. She is the 11th-ranked player, according to clay Elo, as the surface is not well-suited for her game. Her flat and offensive groundstrokes are neutralized on the clay (56% career winning percentage compared to 70% on hard). She has never made it past the third round at Roland Garros and has never reached any tournament final on clay. Osaka’s low probability could be attributed to her small sample size of clay court matches. She’s only played at Madrid and the Italian Open this year but lost in the second and first round, respectively, to unseeded players. All eyes will be on Osaka both on and off the court as she recently announced that she will skip all press conferences and face any potential fines, citing mental health concerns.
Serena Williams: There is no denying that Williams is always a threat whenever her name is in a Grand Slam draw. Ever since winning her 23rd Slam in 2017, all eyes have been on her to see if she can tie Margaret Court’s record. Williams enters the French as the No. 7 seed but has only a 0.5% chance to tie the record. While this might seem surprising, she ranks 27th in clay Elo (13th overall), and like Osaka, clay is Serena’s weakest surface due to her game style, having won only three of her 23 slams at Roland Garros. She hasn’t made it past the fourth round since 2016. More recently, Williams has also only played two warm-up tournaments, both with early-round exits. As the No. 7 seed, she’ll have to go through some tough opponents like Angelique Kerber (No. 26 seed) in the third round or Petra Kvitova (No. 11 seed) in the fourth, who would both be favored over Serena (57% and 71% respectively) despite being seeded lower. Serena and Kerber have met in three Grand Slam finals (2016 Australian Open, 2016 and 2018 Wimbledon), and Kerber has won two. Even if Serena could get through these early tough matches, they might tire her out (especially on clay with longer matches) and prevent her from a deep run. Serena’s overall probability of winning the French might be heavily discounted, but don’t look for this Slam to be the one where she ties the record.
Next Favorites and Dark Horses
Iga Swiatek: One of the most exciting young players on the WTA tour, and only 19 years old, Swiatek is No. 9 in the world and already has her first Grand Slam under her belt. She cruised to victory at last year's French Open, not dropping a single set or having one even go past 6-4. Swiatek is coming off a dominant tournament win at the Italian Open, defeating Karolina Pliskova 6-0, 6-0 in the final. Unlike some of the other players already discussed, Swiatek’s best surface is clay, where she has an 81% career winning percentage (63% on hard). It’s no doubt that Swiatek has the second-highest probability to win at the French at 15%. She benefits from a relatively easier draw, which could see the rematch of last year’s final against No. 4 seed Sofia Kenin in the quarterfinals. Swiatek would be the heavy favorite with an 83% chance of winning that matchup. Swiatek could be the first player to go back-to-back at the French since Justine Henin in 2005-2007.
Garbine Muguruza: Muguruza sees one of the highest jumps in her probability relative to her No. 12 seed, as she is the fifth most likely to win at 7%. The Spaniard is the fourth-ranked player by clay Elo and has seen her greatest Grand Slam successes at the French (81% winning percentage), which she won in 2016. As a double-digit seed, Muguruza could provide some trouble for higher seeds in the early rounds, including a potential fourth-round match with Swiatek. This meeting of two former Roland Garros winners could make for one of the most exciting of the tournament (Swiatek is slightly favored at 57%).
Coco Gauff: One of the biggest draws right now in women’s tennis, the 17-year-old Gauff burst onto the scene at Wimbledon in 2019, defeating Venus Williams on her memorable run to the fourth round as a qualifier. Since then Gauff has been steadily rising and currently ranks a career high 25th on the WTA tour. She will enter her first Grand Slam as a seeded player. While Gauff’s clay Elo ranking is slightly lower than her overall Elo rank (14th vs. 11th), this discrepancy is not nearly as large as some of her American counterparts. Gauff is also coming off a solid run to the semifinals at the Italian Open and her second career title at the Parma Challenger in both singles and doubles. Look for Gauff to recapture some of the 2019 Wimbledon magic; she has the highest probability of winning of any American while also being the youngest. The only thing standing in her way is a potential fourth-round meeting with No. 1 seed Barty. Gauff would have a 25% chance of winning that one. While Barty just retired to Gauff at the Italian Open (even though she still won the first set), this likely won’t happen in a Slam, and Gauff would have to beat her outright.
Sofia Kenin: Last year’s French Open, where she lost in the finals to Swiatek, might actually mark the start of Kenin’s struggles. From the start of the year and the Australian Open, Kenin is just 2-6 and has suffered many early-round exits at the hands of unseeded players. Remarkably, she’s only fallen one spot to No. 5 since the start of the year, likely because the 2021 WTA ranking system is protecting older points due to COVID-19. Elo, however, recognizes her recent struggles, ranking her 26th overall and 40th on clay. Similar to other Americans, clay is Kenin’s weakest surface, where she has a career losing record of 11-14. Kenin is actually one of only two of the 32 seeds that is an underdog in their first-round match, being given just a 44% chance of defeating No. 44 ranked Jelena Ostapenko. With a slim probability of 18% to make the second weekend, it doesn’t look likely Kenin will return to old form at Roland Garros this year.
Jennifer Brady: Similar to her American counterpart Kenin, Brady is the only other seeded player who is an underdog in her opening-round match: Her chances against Anastasija Sevastova are 45%. While Brady has technically been the most recently successful American in terms of Grand Slam performance, making runs to last year’s US Open semis and this year’s Australian finals (losing to Osaka both times), she has a mere 2.2% chance to make the quarterfinals. Elo is a rating that factors in both historical performance and strength of competition. Even though the former UCLA Bruin NCAA champion has been good of late, she’s never made it past the second round at the French, and on her two recent runs, the highest seed she had to face was No. 17 Angelique Kerber (U.S. Open fourth round). She also recently parted ways with her coach, which could create some extra turmoil right before the tournament. Brady could see an intriguing all-American third round match against Coco Gauff, but would have only a 34% chance of winning.
The women’s side of the French Open, with its long rallies and frequent upsets, always brings the promise of a first-time winner and a potential emerging young star, and this year is no different. The top of the field sees a mix of seasoned veterans and young guns, all with solid shots of winning at Roland Garros.