By David Arkow
With 120 singles matches completed on the women’s side of the draw, that provides a great opportunity to look back at some of the best matches so far and look forward to the exciting matchups to come in the final weekend. At the start of the tournament, we simulated the original draw to give all players a probability not only to win the whole tournament but also to reach a specific round. For example, at the start of the tournament, No. 8 seed Iga Swiatek had a 45% chance of reaching the quarterfinals given that she had to win four matches to get there. Now that Swiatek has reached the quarters, along with 7 other players, we can run a new simulation to give new probabilities for each of the remaining players to advance. Obviously, all of their current probabilities to win the title will be greater than their original as there are only 8 players remaining (3 rounds) as opposed to the initial 128 players (7 rounds).
Model Check In
Now that more than half of the tournament is complete (and 95% of the total matches), we can reflect back at how successful the simulation was. Quantifying success does not mean that the favorite (>50% chance) should win all the time. After all, it is sports and that never happens. Rather an accurate model would correctly predict those players with a 70% chance of winning to win 7 out of 10 times. It should be very accurate at picking heavy favorites and less accurate at picking closer matches to make sure that it is calibrated correctly. Some overall trends from the tournament find that upsets (when one player has less than a 50% chance of winning) occurred 29% of the time in the first round, 21% of the time in the second round, 40% in the third round, and 25% in the fourth. The women’s side had many more upsets than the men’s side with a 28% overall upset rate compared to 23% for the men’s.
Big Upsets (and Withdrawals)
Having a draw with 128 players, there is pretty much guaranteed to be some big upsets. Using the initial simulation, we can quantify exactly how rare certain upsets are rather than just looking at the seeds or rankings of players. After the first four rounds of the tournament, here are some of the most surprising upsets.
Who would have thought that going into the tournament, Osaka would have defaulted before her second round match with no physical injuries. Osaka announced that she would pull out after she was fined for skipping her first round press conference and warned that she could face further punishment including increased fines or even default. Osaka proves that math and analytics can never predict everything and serves as a great reminder of the human element of sports. While the simulation did not give her high odds, only a 4% chance of winning and a 43% chance of making the second week, it did not forecast a withdrawal. It remains to be seen when Osaka will return to playing matches as Wimbledon is less than a month away, but all fans will be awaiting her return.
Just two days after Osaka pulled out, overall favorite Ash Barty retired in the middle of her second round match against No. 45 ranked Magda Linette. Barty left after dropping the first set 6-1 with a hip injury which had started the week before the French. Barty also retired in her last tournament at the Italian Open but that was with an unrelated arm injury. Obviously, the simulation did not predict this and Barty’s withdrawal (along with Osaka’s) opens it up for the rest of the competition in an already wide open women’s field. No. 11 seed and 2020 semifinalist Petra Kvitova also defaulted before her second round match and she had the fourth highest title odds (8%) of the field. It would have been hard to envision that the top three women in the world (Barty, Osaka, Halep) would all pull out of the French Open but that is the unpredictable nature of sports. Hopefully these stars can get healthy for Wimbledon which starts in less than a month or tennis fans might see a brand new name at the No. 1 seed.
Serena’s run was cut short by No. 21 seed Elena Rybakina but she shouldn’t be too disappointed given that she only had an 8% chance of making the quarters at the outset of the tournament and was only the slight favorite in this match with a 58% chance of winning. American tennis fans can still be happy with their performance as four of the players in the Round of 16 were American (Sofia Kenin, Madison Keys, Coco Gauff, Sloane Stephens) while no male Americans made it that far.
Predicting the Rest of Roland Garros
There are lots of new faces among the remaining eight women in the draw as seven of the players are in their deepest Grand Slam runs of their careers. The average ranking of the female quarterfinalists is 33 compared to 10 for the men’s. Of the top 10 seeds, only Iga Swiatek remains and for the first time in Open Era history, there is no top five seed in the quarterfinals.
The marquee quarterfinal matchup is probably between the two highest remaining seeds in No. 8 Swiatek and No. 17 Maria Sakkari. Swiatek has been the most dominant player in the tournament not having dropped a set. Sakkari has also been solid, just knocking out No. 4 seed Sofia Kenin and thwarting a rematch of last year’s final between Swiatek and Kenin. Swiatek is still the biggest favorite to win her quarterfinal match at 74%, but Sakkari should prove to be her toughest test yet. Swiatek entered the tournament with the second highest probability at 15% (behind Ash Barty) and enters the quarters with nearly split odds with the rest of the field to win the title at 45%. Swiatek could be the first repeat French Open champion since Justine Henin (2005-2007) and one of the youngest as she just turned 20 during the tournament.
Another highlight of the tournament has been Coco Gauff amidst her deepest Grand Slam run of her career. Similar to Swiatek, Gauff also hasn’t dropped a set. Despite being the fourth highest seeded American woman (behind Kenin, Williams, and Keys), Gauff had the highest initial probability of winning the tournament (1.5%) of all American women. Similar to the potential men’s semifinal with Rafa and Novak, a potential Swiatek-Gauff semifinal seems that it could determine the women’s champion with the two having the highest remaining probabilities of winning. This would be an exciting rematch of the Italian Open semis which Swiatek won in two tight sets. If Swiatek and Gauff meet in the Roland Garros semis, Swiatek would have a 72% chance of winning.
The bottom half of the draw isn’t as exciting but it guarantees that we will see a double digit seed outside of the twenties in the finals. No. 33 seed Paula Badosa is the favorite to advance out of that half (38% chance of reaching finals) and has a 13% chance of winning the tournament. She benefits from an easier draw facing the lowest ranked player remaining No. 85 Tamara Zidansek. She did just win the Serbia Open and reached the semis of Madrid where she lost to Barty so there is reason to believe her recent success.
The women’s side of the French Open has proven to be full of exciting upsets allowing new stars to emerge in the final weekend. Fans have lots to root for whether it is for repeat champion Swiatek or any of the other players who would be first-time champions.
David Arkow '24 is an economics major and member of the Harvard Varsity Men's Tennis Team. He also serves on the board of HSAC. If you have any questions about this article, you can reach out to him darkow@college.harvard.edu. You can check out his original preview of the women's draw along with his updated preview of the men's draw.
