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This year’s U.S. Open sets the stage for one of the most remarkable feats in all of sport, as Novak Djokovic will attempt to be the first male tennis player to win the calendar-year Grand Slam since Rod Laver in 1969.
Not only would he achieve a milestone neither Roger Federer nor Rafael Nadal has claimed, but Djokovic would also surpass both of those icons for the most career Grand Slam titles, with 21. Federer (knee) and Nadal (foot) have both pulled out of the tournament due to injury, paving the way for the top-ranked Djokovic. It will be just the second time in the history of the Big 3 that only one of the trio will be in the field of 128 (the 2020 U.S. Open was the other). Still, it will not be a cakewalk for Djokovic, as a new guard of men’s tennis stars begins to assert itself. While Djokovic will look to solidify his case for the GOAT title, he could face a challenge from one of a handful of younger, promising competitors.
Trying to predict outcomes with probabilities 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. Grand Slam probabilities are interdependent and can change meaningfully with each result. For example, if Djokovic were to lose in an earlier round in the draw (as unlikely as that might be), No. 2 seed Daniil Medvedev’s probability of winning would go drastically up, since he would no longer have to play Novak.
Nevertheless, we can still try to predict the U.S. Open outcome through a simulation. For my simulation, I used Tennis Abstract’s Elo ratings, which can be adjusted for different surfaces. For example, Medvedev ranks second in Elo on hard courts but 10th on clay. 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, and of winning. For instance, if Djokovic wins the simulation 3,000 out of 10,000 times, he has an approximately 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 possibilities for many interesting matchups throughout the tournament, with potential upsets to star players.
Novak Djokovic: The Serb enters the field as the favorite with a 23% chance of winning. Nevertheless, out of his 20 total Slams, only three are from the U.S. Open. He exited in the fourth round in his last two entries without even completing his matches; he retired due to injury against Stan Wawrinka in 2019 and was disqualified against Pablo Carreno Busta in 2020 after accidentally hitting an umpire with a ball. Some fans think they saw a potential crack in Djokovic after he lost to Alexander Zverev in the semifinals of the Tokyo Olympics and then threw his racket into the stands in his defeat to Carreno Busta in the bronze medal match. Djokovic skipped all the hard court warmup tournaments to make sure he is fully rested. The betting markets currently have him as a -150 favorite, giving him an implied probability of 60% with 127 others also vying for the title.
Daniil Medvedev: The Russian has nearly the same odds as Djokovic to take the title, at 22%. The margin is as tight as it’s been all year against Djokovic, as Medvedev ranks a mere six Elo points behind Djokovic (Berrettini, who was second on grass, was more than 100 points behind Djokovic). The Russian’s flat and penetrating baseline strokes are well-suited for the fast-paced hard courts, and it is his best surface. The U.S. Open has been his most successful Slam, where he made the finals in 2019, losing a five-set thriller against Nadal and falling in last year’s semis to eventual champion Dominic Thiem. While Djokovic has skipped hard court warmups, Medvedev has had a stellar runup to Flushing Meadows, winning the Canadian Masters 1000 and reaching the semis at the Cincinnati 1000. This could be a reason Medvedev Elo is so high, but it also feeds into a critique of the 25-year-old—that he dominates lower-level tournaments without having a Slam to his name. Nevertheless, Medvedev has as good a record as any against Djoker (3-5) and might have the opportunity to take him down in a rematch of this year’s Australian Open Final to thwart the calendar Slam. A chalk final between the two would be a great showdown, as it is nearly a 50-50 tossup.
Alex Zverev: Only five players have taken down Djokovic this year, and Zverev did it on arguably the biggest stage, defeating him, 1-6, 6-3, 6-1, in the Olympic semifinals. He then cruised to the title against Russia’s Karen Khachanov, 6-3, 6-1, becoming the first male German tennis gold medalist. He just won the Cincinnati Masters despite never making it past the second round in his last six entries. Zverev lost in a heart-breaking five-setter against Dominic Thiem in last year’s U.S. Open final after being up two sets to none. While that was his best Slam run to date, that match still haunts him. He looks poised to make another deep run in Queens as the third overall favorite in the field with a 17% chance at the title.
Stefanos Tsitsipas: It has been a career year for Tsitsipas, and he now enters the draw with his highest ATP ranking at No. 3. The Greek made the semis at the Australian Open, his first Slam final at Roland Garros, but then suffered a first-round upset at Wimbledon. While Tsitsipas is not as dominant on the hard courts as he is on clay (65% vs 74% career winning percentages), he enters the U.S. Open in solid form, making the semis at both Masters 1000 warmups. He has struggled in Queens in the past, never making it to the second weekend. He has an intriguing first round matchup against 2012 U.S. Open Champion Andy Murray but should get through (76% favorite). Nevertheless, given the success he has had this year and in the tune-up tournaments, he has an 8% chance to take the title.
Matteo Berrettini: Since testing Djokovic in the Wimbledon final, Berrettini has only played one tournament, at Cincinnati, where he lost in the second round. Fans might remember his thigh being taped up in that match, nursing an injury that forced him to miss the Olympics and could affect him in New York. Going into Wimbledon, our simulation had him with the second-highest odds of the field, despite being the No. 7 seed. Now, he has the 11th highest odds despite being seeded sixth. Coincidentally, Tsitsipas saw the same regression after making it to the finals of the French: Our Wimbledon simulation projected the Greek star with much lower odds, and he lost in the first round. The same fate could befall Berrettini, who only has a 31% chance to make the second weekend, and is also in Djokovic’s quarter.
Denis Shapovalov: Similar to Berrettini, it’s hard to imagine seeing Shapo as an overrated player after he made the semis at Wimbledon. But since then, Shapovalov has had three consecutive first-round exits, all as a Top 10 seed. The highest-ranked Canadian enters the draw with his highest Slam seed ever at No. 7, but he only has a 29% chance to make the second weekend. However, the U.S. Open is historically his best Slam, where he has a 73% winning percentage and made the quarterfinals last year.
This might be the most optimistic moment in American men’s tennis for the past decade. After years of decline, with only nine players ranked in the Top 100 at the end of 2020, there are currently 14 Americans in that exclusive club, more than any other country. There are also 21 Yanks in the Open draw (though some are wildcards). The highest-ranked American, at No. 23, and tallest player in the Top 100 at 6-11, Reilly Opelka just made it to the finals of the Canadian Masters 1000. Jenson Brooksby, a 20-year-old wildcard, is one of the hottest young players on the Tour, making his first ATP 250 final in Newport and the semis at the D.C. 500. His fierce rival from the U.S. junior circuit, Brandon Nakashima, also received a wildcard and has been playing his best tennis, making the finals of two consecutive 250s in Mexico and Atlanta. Along with the young guns, there is also veteran John Isner, who just won Atlanta and made the semis of the Canadian Masters 1000. Interestingly, Nakashima has played eight consecutive tournaments where he has faced a fellow American, and the streak will continue as he faces Isner in an exciting first rounder (the two have played twice in the last month). This U.S. Open could mark a turning point in American men’s tennis, with the rise of a potential future Slam champion. It probably won’t be this year, as the Americans have a combined probability of about 4% of taking the title in front of the home crowd, but there are many competitive players poised to make a deep or breakout run.
The 2021 men’s U.S. Open may prove to be a significant milestone in tennis history. It could mark the crowning of what is starting to seem like an undeniable GOAT in Novak Djokovic, if he wins the calendar Slam and surpasses Federer and Nadal. But mathematically, there are many other players who have solid shots at the title and might thwart history. This Slam very well could be one for the ages.