With his French Open win earlier this month―his 19th career Grand Slam―Novak Djokovic now trails Roger Federer and Rafael Nadal by only one for the all-time Slam record. And now, going into Wimbledon, which begins today, the world No. 1 and the overall favorite is in prime position to pull even with his rivals, especially given that Nadal has pulled out to rest his body and Federer has not won an ATP title since 2019. Still, grass is Federer’s best surface, and Wimbledon is his best Slam. He’s won eight titles at the All-England Club.
Meanwhile, home-crowd favorite Andy Murray is returning to his first Wimbledon since 2017. And then there is the rising class of young stars―Daniil Medvedev (French Open quarterfinalist), 25; Stefanos Tsistipas (French Open runner-up), 22; Alexander Zverev, 24 (French Open semifinalist); and Matteo Berretini, 25 (French Open quarterfinalist)―who seem ready to break through the Big 3 monopoly at any moment. Simulating the tournament using adjusted Elo ratings, I calculated the estimated probabilities for every 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’s much easier for a single game between two teams or even your standard 16-team playoff bracket than for a Grand Slam tennis tournament with a draw size of 128. So many probabilities are interdependent that they can change meaningfully with each result, particularly an unexpected one. For example, if Djokovic were to lose in an earlier round in the draw (as unlikely as that might be), Federer’s probability of winning a ninth Wimbledon title would go up drastically.
Nevertheless, we can still try to predict the outcome of the tournament through a simulation. For mine, I used Tennis Abstract’s Elo ratings, which can be adjusted for different surfaces. For example, Federer is 17th in overall Elo, but 10th on grass. Now with the actual draw, we can simulate the tournament thousands of times to see the different potential outcomes. We used this same approach to simulate what would happen at Roland Garros just two weeks ago. This will ultimately give us a probability for each player making a certain round or even winning. For instance, if Djokovic wins the simulation 3,000 out of 10,000 times, he has approximately a 30% 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 or a No. 32 seed in the third round. This creates for many interesting matchups throughout the tournament with potential upset opportunities to the star players.
In addition, grass courts, as opposed to hard and clay, likely have the most upsets as it is the most unfamiliar for players. This year, with so few warm-up tournaments between the French and Wimbledon, players aren’t as fine-tuned for the sharp transition from the slowest to the fastest surface. Given that some players won’t have played on grass in more than two years―there was no grass court season in 2020 because of the pandemic―this year’s tournament could also greatly advantage certain playing styles (big servers, volleyers, slicers).
The Big 3 (Minus 1)
Novak Djokovic: Fresh off his triumphant five-set comeback final at Roland Garros, Djokovic will roll into London the heavy favorite, greatly boosting his case for the GOAT title after knocking out the King of Clay, who hadn’t lost at the French (105-3 all-time) since Djokovic beat him in the 2015 quarters. With the absence of Nadal, his fiercest competition at the moment (and likely of all time), Djokovic’s odds to win his sixth Wimbledon have improved even more with a 38% chance to win No. 20. The only cause for concern might be fatigue, after playing a total of 21 hours at the French. While most fans consider Federer the best grass-court player, Djokovic has quietly been dominating the surface, winning 88% of his matches at Wimbledon. As of now, Djokovic would likely also be the favorite at the U.S. Open, and he could be the first person to win the calendar Grand Slam since Rod Laver in 1962 and 1969.
Roger Federer: Entering the draw seeded No. 6, Federer has 10th-highest overall odds with a 3% chance of taking the title. After a solid run to the fourth round at Roland Garros, Federer pulled out of the French, simultaneously proving he can still knock out the easier competition and showing his age. Federer had an unusual second round knockout by No. 16 seed and 20-year-old Felix Auger Aliassime at Halle (where he has 10 career titles). Federer has won a grass court tournament all but one year (2010) since 2003 and has made it clear that his priority is Wimbledon. And depending on his performance, some fans are speculating that this could be his last. But Federer has only won a single Wimby match against Djokovic (2012 semifinals) and has lost to him in three consecutive finals, including 2019’s epic in which Federer dropped two heartbreaking fifth-set match points. This time around, Federer would have a mere 20% percent chance of defeating Djokovic.
Next Favorites and Dark Horses
Matteo Berretini: Berretini has quietly been one of the most consistent Top 10 players over the last two years. With his strong serve―he holds 89% of service games, good for fifth on tour―and a big forehand, Berretini, who ranks seventh in overall Elo, comes in second on grass. This is likely due to his recent success winning the 250 Stuttgart in 2019 and the 500 in Queen’s Club last week. His best Wimbledon run was in 2019 to the fourth round, where he was quickly dispatched by Federer, only winning five total games. Berretini will look to capitalize on his recent run to the French Open quarters (pushing Djokovic in a tough four sets), and make an even deeper run on his best surface. He has the second highest odds in the draw at 9% and would be Djokovic’s toughest opponent with a 31% chance of taking him down.
Felix Auger-Aliassime: The highest-ranked Canadian has been touted as one of the most talented young players on the Tour. A first-round French open exit allowed Auger-Aliassime to play the Stuttgart Open, in which he lost to former Wimbledon finalist Marin Cilic in the finals (he is 0-8 in finals in his career). He also made a run to the semis at Halle where he defeated Federer in three sets. Auger-Aliassime has only played Wimby once, in 2019, making it to the third round before being knocked out by Frenchman Ugo Humbert (whom he split matches against recently in Stuttgart and Halle). If both were to win their first matches, they would again face each other in the third round in one of the most competitive matches of the tournament (Humbert would have a 52% chance). With a more open field, this year’s Wimbledon provides a great opportunity for Auger-Aliassime to make his deepest career Slam run.
Big-Serving Americans: No American man has won a Grand Slam since Andy Roddick won the 2003 U.S. Open. Despite the American men severely struggling on clay with no one making it past the third round (average round of 1.8 for 12 players), they are much more likely to perform better at Wimbledon. This is because the top three ranked Americans―No. 27 Reilly Opelka (6’11’’), No. 28 John Isner (6’10’’) and No. 31 Taylor Fritz (6’4’’)―have some of the biggest serves on tour. Isner and Opelka, who won Junior Wimbledon in 2015, lead the ATP in aces per match (20.5 and 18.6) and rank second and fourth, respectively, in hold percentage (92.5% and 89.3%). These numbers will only be emphasized more on grass. Isner is famous for his three-day 11 hour marathon match in 2010 against Nicolas Mahut. With some other dark horse Americans in the field―like 2017 semifinalist Sam Querrey, who is ranked No. 63 but 17th by grass Elo―it is likely that at least one will make a deep run at Wimbledon.
Baseliners: Lumped into this group are some of the best “counterpunchers”—players who make fewer errors and rely more on opponent errors—on tour. Their game style is not as well-suited for grass, as they need longer rallies and more opportunities for the opponent to miss. Grass produces shorter points, favoring big servers and hitters. None of the counterpunchers has a huge serve. Take, for example, No. 9 Diego Schwartzman, who averages the fewest aces per match (1.5) in the entire ATP. All of them are clay-court specialists and had very solid French Opens: Schwartzman (32nd in grass Elo) made the quarters; No. 11 Pablo Carreno Busta (60th in grass Elo) made the fourth round; No. 12 Casper Ruud (46th in grass Elo) made the third; and No. 17 Cristian Garin (28th in grass Elo) made the fourth. Busta, Ruud and Garin have never won a single match at Wimbledon despite nine collective entries among them, and Schwartzman has only made it as far as the third round. Perhaps they will find a way to pull through on a surface that is not friendly to them, but it would not be surprising if some of these higher seeds are among the bigger upsets early on.
Wimbledon is the most prestigious of the four Slams and is often considered the most coveted by the players. The surface makes for an exciting tournament with lots of intriguing stylistic matchups―big serves, explosive shots―and surprising upsets. This year’s field sees the favorite Djokovic try to knot up the Big 3 race, the long-awaited return of Federer for what could be his last Wimbledon, the continued success of new stars like Tsitsipas or Auger-Aliassime, or the best shot for the American field. This year’s Wimbledon will prove to be vital in the Big 3 race and is guaranteed to be one for the history books.
David Arkow is a sophomore economics major and a member of the Harvard men’s varsity tennis team.