How Favorites Fly Around the Board: Jessica Pegula and Belinda Bencic at Wimbledon

Coming into today (Day 3 at Wimbledon), my simulations had Jessica Pegula as the 2^nd favorite to win the tournament, with a 15.4% probability of bringing home the Venus Rosewater dish and Belinda Bencic a fairly distant 3^rd at 10.9%. They both won today, but their title chances completely reversed. Now, Bencic is the 2^nd favorite at 17.5% while Pegula has slipped below both Bencic and Madison Keys to 4^th favorite at 8.6%. But how does something like this happen? Thanks to the Dweck Sports Tournament Simulator, we have an answer. And it’s a little bit complicated.

We start with the straightforward part – the player Bencic beat today, Xinyu Wang, is better than the player Pegula beat, Sara Sorribes Tormo. So, Bencic gets a larger boost to her title chances than Pegula does just by staying in the tournament. But the big moves are still coming.

The first major change is in Bencic’s odds of reaching the Round of 16. Coming into today, they were at 72.4% (83.8% conditional on Bencic beating Xinyu Wang). Now, they have jumped up to 87.2%. While any number of factors could be involved in this change, Bencic’s head-to-head record against each of her potential 3^rd Round opponents is certainly one of them. Bencic and Diane Parry have faced off just once, a Bencic victory from 2022, while she is a more established 3-1 against Anna Kalinskaya. After Kalinskaya beat Parry, Bencic’s path through to the second week got a little bit easier.

The next difference is in the probability that Bencic reaches the semifinals, increasing from 32.6% to 45.6%. The impact there comes from the conditional probability that Bencic wins her quarterfinal jumping from 57.2% to 64.9%. And the reasoning behind that sends us back to Jessica Pegula.

Through today’s action, the probability that Jessica Pegula would reach the Round of 16 went from 88.9% to 88.8%, a change more likely explained by largely meaningless statistical noise than anything else. But the probability that she reaches the Quarterfinals dropped from 66.7% to 56%. The only possible explanation that I could find for that dramatic a change is that Iva Jovic beat Tatjana Maria today. Jovic and Pegula draw into each other in the Round of 16. That was already the third-most likely Round of 16 matchup in the women’s draw, but out of my 25,000 simulations, it now happens an ADDITIONAL 7,196 times. These two are on a collision course. And while Pegula would be favored in the Round of 16 regardless of the opponent, a matchup with Jovic is the worst case scenario. So how, you might ask, does this help Belinda Bencic’s conditional quarterfinal win probability so much? They are in the same quarter.

The dominoes do not end there. For example, the fact that World #1 Aryna Sabalenka will likely have to go through Jelena Ostapenko and Naomi Osaka to even reach the quarterfinals increases the likelihood of a weaker semifinal opponent being fed to whoever comes out of the Pegula/Bencic/Coco Gauff (who I haven’t even mentioned yet) quarter, and the cracks continuing to show in Elena Rybakina’s game increase the real estate for Madison Keys, Linda Noskova, and even Marie Bouzkova to be across the net from them in the final.

Just coming out and saying “Jessica Pegula and Belinda Bencic flipped in the middle of the tournament” might sound counterintuitive. But thanks to the Dweck Sports Tournament Simulator and associated Matchup Probabilities, Scoreboard Watching Guides, and Tournament Outlooks, we can make some sense out of the endless moving parts of the early stages of a Grand Slam. It might be easier to talk about our tournament favorite, Iga Swiatek. For the defending champion, it is clear skies all the way to the semifinals.