Updated September 8, 2026
Ben Shelton and Carlos Alcaraz meet Tuesday night in one of the most intriguing quarterfinals of the 2026 US Open. Shelton has played himself into peak form at exactly the right time, while defending champion Alcaraz has quickly erased most concerns surrounding his four-month absence because of a wrist injury. Polymarket currently prices Alcaraz around 79¢, implying a 79% chance of advancing, with Shelton around 22¢. Is Shelton’s booming serve and Arthur Ashe Stadium support enough to justify giving the American better than a one-in-five chance against a player who has never lost to him?
Why Our Model Sees Value:
“Shelton’s serving numbers and home-crowd advantage make him a dangerous opponent, but the current price gives too much weight to those factors and Alcaraz’s recent injury layoff. Alcaraz has already shown that his wrist is holding up, has beaten Shelton in all 3 previous meetings, and has the superior return game to neutralize the American’s biggest weapon.”
Is Shelton's Run Misleading?
Ben Shelton has won each of his matches at this year's US Open in 4 or fewer sets. He's defeated Hubert Hurkacz, Stefanos Tsitsipas, and Denis Shapovalov along the way, which looks impressive on paper. But all three of those men are not playing their best tennis, which should be taken into account.
Market Pricing Implies 4 Set Match Expected
Polymarket pricing lists Alcaraz as the favorite at -1.5 sets, while Shelton is favored at +2.5 sets, implying an expectation that this match will be decided with Alcaraz winning in 4 sets.
Recommended Prediction:
Alcaraz to Win
Current Market Price:
79¢
Model Win Probability:
83%
Market-Implied Probability:
79%
Model Edge:
4%
Buy Up To:
81¢
Model Trade Confidence:
72/100
Alcaraz enters this quarterfinal with a 3-0 record against Shelton. Their meetings have come on different stages and surfaces, yet the result has stayed the same. Their latest match came at the 2025 French Open, where Alcaraz won 7-6(8), 6-3, 4-6, 6-4. Shelton did enough in Paris to show that his power can trouble the Spaniard, becoming more competitive than he had been in their earlier meetings. Still, Alcaraz found the answers across four sets and eventually went on to win the tournament.
Alcaraz has been particularly dominant against American players at majors. He has won each of his previous 13 Grand Slam matches against Americans and has captured 39 of 46 sets in those contests. Shelton will need to do something that no American has yet managed against Alcaraz at a major.
Shelton’s route to the quarterfinal has been more demanding than Alcaraz’s. After dropping the opening set against Tallon Griekspoor in Round 1, Shelton recovered to win in four. He then beat Hubert Hurkacz 6-3, 5-7, 7-6(3), 7-5 before surviving another four-set match against Denis Shapovalov, 7-6(3), 6-7(5), 6-3, 6-4.
His fourth-round victory was much cleaner. Shelton overwhelmed Stefanos Tsitsipas 6-2, 6-3, 6-4 without facing a break point. He struck 11 aces and won 83% of his first-serve points, easily his most convincing performance of this US Open.
Shelton believes he is serving and returning better than he was when he faced Alcaraz in Paris, with improved movement and greater consistency from the baseline. Those changes could give him a better chance of extending the match than the 79% market price might initially suggest.
The major question surrounding Alcaraz before the tournament was his right wrist. He had gone more than four months without competing before returning in New York.
His first-round performance against Roman Safiullin was efficient rather than spectacular, but Alcaraz won 6-4, 6-4, 6-4 and showed no obvious physical limitation. He then lost the first set against Jaime Faria before winning the next three, followed by a 6-3, 6-4, 6-1 victory over Wu Yibing.
Any lingering doubts became harder to defend after his fourth-round match. Alcaraz beat Tommy Paul 6-4, 6-3, 6-4, reaching his 15th career Grand Slam quarterfinal and extending his run of major victories to 18 consecutive matches. At this stage, pricing a meaningful injury discount into Alcaraz’s probability looks increasingly difficult to justify.
Shelton has one obvious route to making this close: to serve at an elite level and shorten as many points as possible. If Shelton lands first serves at a high rate and wins something close to the 83% of first-serve points he captured against Tsitsipas, Alcaraz may struggle to generate enough break opportunities to create separation. Shelton can also use the left-handed serve out wide in the ad court to pull Alcaraz away from the middle before attacking the open court.
The issue is that Alcaraz is far better equipped to defend that pattern than Tsitsipas was. Alcaraz’s return positioning, speed, and ability to turn defensive balls into neutral rallies can force Shelton to hit an extra shot. Shelton is at his best when points are decided in the first few strikes. Once exchanges become longer and require repeated direction changes, Alcaraz has a much better chance of winning those points.
There is one element that previous meetings between these players cannot fully account for, and that is Shelton playing Alcaraz in New York. Shelton reached the US Open semifinals in 2023 and has repeatedly fed off the energy inside Arthur Ashe Stadium. Even Alcaraz acknowledged that Shelton uses the home crowd effectively.
A loud night session could become a factor if Shelton starts quickly. Holding serve through the opening games and getting the crowd involved could create a very different atmosphere from their previous meetings.
Still, crowd support can only carry the matchup so far. Shelton must repeatedly protect serve while creating pressure on an opponent who has lost just one set through four rounds.
The first-set serving numbers should tell us plenty about whether or not Shelton can put together a serious upset bid on Tuesday night. Shelton needs cheap points. If Alcaraz consistently gets returns into play, the Spaniard’s advantage grows because he is better equipped to win points after the initial serve-plus-one sequence.
Shelton has enough power to take a set, particularly if his first serve approaches the level he showed against Tsitsipas. But sustaining that performance over a best-of-five match against Alcaraz is a much tougher assignment.
Polymarket’s 79% implied probability is already giving Alcaraz considerable respect. My projection still lands higher at 83%. The gap is not enormous, but it is large enough to make Alcaraz my position at the current 79¢ price.
