Week one, and the draw is already unrecognizable. Jannik Sinner — the world number one — pulls out before hitting a single ball, a knee injury ending his title hopes before they begin. Novak Djokovic, four-time champion at Flushing Meadows, falls in five sets to Argentina's Mariano Navone in the first round, visibly ill, vomiting courtside across the final two sets (7-6, 5-7, 4-6, 6-2, 6-1 in 4h36). It's the first time in the modern era that none of the Big Three reached the second round of a Grand Slam at the US Open.
The ATP draw is wide open. Our model ran the hard court numbers to find the eight most likely quarterfinalists and four most likely finalists on both sides of the net. Here's what it says — and where it parts ways with the market.
Key takeaways - Alcaraz remains the ATP favorite (~33% win probability) with a bracket that softened dramatically after Djokovic's R1 exit - WTA: Sabalenka is the defending champion but our model flags Gauff's exceptional hard court form in 2026 (30-6 on the surface this year) - Three hard court signals dominate our model for the second week: ace rate, service games won, and return games won - ProbWin tennis model over the past 30 days: 68.3% win rate, +13.44 units (n = 120 official picks)
A Draw Turned Upside Down in Week One
Nobody expected the US Open to open like this. Sinner, who should have been the player to beat, is sidelined before the tournament even starts. Djokovic's five-set loss to Navone — while battling what appeared to be a severe stomach illness — marks the first time Djokovic has ever lost in the opening round at the US Open.
The bracket implications are immediate:
| Player | Status | Bracket impact |
|---|---|---|
| Jannik Sinner | Withdrew (knee injury) | Zverev inherits the #1 seed |
| Novak Djokovic | Lost R1 to Navone | Alcaraz's half of the draw opens up |
| Carlos Alcaraz | In draw, defending champion | Path to final now significantly easier |
| Alexander Zverev | #1 seed, draw intact | Carries the burden of top billing |
The half of the draw that Alcaraz occupies — which was supposed to include a potential Djokovic semifinal — is now the most accessible path to a final in years. Our model accounts for this, and it shows.
For our pre-tournament analysis, see our US Open 2026 AI preview.
ATP: What Our Hard Court Model Actually Measures
Before calculating match probabilities, our system evaluates three surface-specific signals for every player:
Signal 1 — Ace rate on hard court
Threshold: ace rate > 12% = meaningful server advantage
Flushing Meadows specifics: windy conditions + lower bounce = bigger serve edge
Signal 2 — Service games won (%)
Strong correlation with win rate in best-of-5 matches
Quarterfinalists and beyond: this ratio separates the contenders
Signal 3 — Return games won (%)
Measures offensive pressure on return
Gap > 8 points between two players = significant model edge
Alcaraz scores well on all three — ace rate in the ATP top 15 on hard in 2026, 87% service games won on fast surfaces this year, and the strongest return numbers in his half of the draw. Our model puts him at 61% to reach the final from his half — slightly higher than the market implies.
Zverev's side is more contested. Taylor Fritz, who has been in outstanding form on the American hard court swing (Cincinnati, Washington), projects as a likely quarterfinal opponent. Our model gives that matchup to Zverev at 53% — nearly a coin flip, while pre-tournament odds had Zverev at 62% to win that quarter.
Join ProbWin for free
Access our AI predictions for NBA, NHL, Soccer & Tennis. Sign up in 30 seconds.
ATP: Our Four Most Likely Semifinalists
| Player | Seed | QF probability (model) | SF probability (model) | Model note |
|---|---|---|---|---|
| Carlos Alcaraz | #2 | 78% | 61% | Open bracket post-Djokovic |
| Alexander Zverev | #1 | 69% | 48% | Tough quarter vs Fritz |
| Taylor Fritz | #5 | 58% | 31% | Undervalued by the market |
| Arthur Fils | #6 | 44% | 22% | Depends on lower bracket |
Where we diverge from the market: Fritz is meaningfully undervalued in our model. His hard court performance at American events is consistently better than pre-tournament odds reflect — a pattern we tracked across Cincinnati and Washington this year. The market corrects slowly; our model adjusts immediately.
Our predicted ATP final: Alcaraz vs Zverev (39% probability of that exact matchup), with Fritz as the most credible threat to Zverev reaching that stage.
For a deeper look at our methodology, read our hard court tennis predictions guide and our US Open AI analysis.
WTA: Sabalenka vs Gauff — What the Model Says
The women's side has a clearer structure, but it's not as one-sided as the betting lines suggest. Sabalenka is the defending champion and the clear market favorite at +330 pre-tournament. Our model doesn't disagree entirely — but it flags something the odds don't fully capture: Sabalenka's recent form has been shaky.
Seven losses to Top-40 opponents in recent weeks. Three consecutive defeats against Top-20 players heading into Flushing. Our model weights recent form alongside surface data, and the gap between Sabalenka and Gauff closes considerably once that factor is applied.
Gauff's 2026 hard court numbers are exceptional:
Gauff hard court profile, 2026:
→ 30-6 record on all fast surfaces
→ Service games won: 82% (top 5 WTA)
→ Return games won: 38% (top 3 WTA)
→ Break point conversion: above career average
That combination — reliable serve, aggressive return — is exactly the profile our model identifies as optimal for Flushing Meadows. Second-week matches tend to go deep in sets, and players who convert break opportunities on return win those matches at a higher rate. Gauff is above Sabalenka on that metric this season.
WTA: Our Four Most Likely Semifinalists
| Player | Seed | QF probability (model) | SF probability (model) | Market odds |
|---|---|---|---|---|
| Aryna Sabalenka | #1 | 74% | 54% | +330 |
| Coco Gauff | #2 | 71% | 49% | +450 |
| Elena Rybakina | #3 | 63% | 38% | +600 |
| Iga Swiatek | #8 | 55% | 30% | +550 |
The key quarterfinal to watch: Swiatek and Rybakina are in the same quarter of the draw. Our model gives that matchup to Swiatek at 52% — barely ahead, despite the ranking difference. Swiatek's 2026 form has been inconsistent enough that the surface edge doesn't fully compensate. This could be the upset of the second week.
Our predicted WTA final: Sabalenka vs Gauff (34% probability of that exact pairing). If Gauff maintains her current service level, Sabalenka's usual physical dominance is partially offset — our model sees this as the tightest projected Grand Slam final it has calculated in months.
Frequently asked questions
Who is the favorite to win the US Open 2026 men's singles? Carlos Alcaraz, the defending champion, is the favorite at roughly 33% win probability per the market. Our model confirms that position: his half of the draw has opened significantly with Sinner's withdrawal and Djokovic's first-round loss to Navone.
Did Sinner play at the US Open 2026? No. Jannik Sinner withdrew before the tournament with a knee injury. Alexander Zverev was elevated to the #1 seed in his absence.
What happened to Djokovic at the US Open 2026? Djokovic lost in the first round to Mariano Navone of Argentina in five sets (7-6, 5-7, 4-6, 6-2, 6-1), visibly battling illness throughout the match. It was the first time in his career that Djokovic lost in the opening round at the US Open.
Can Gauff beat Sabalenka in the final? According to our model, the matchup is genuinely close. Gauff is 30-6 on hard courts in 2026, with return games won at 38% (top 3 WTA). Her service improvement this year narrows the gap against Sabalenka significantly. Our model projects the WTA final between these two at 34% probability — the most likely scenario of any pairing.
How does ProbWin model tennis predictions? Our model calculates calibrated probabilities from surface-specific data (ace rate, service games won, return games won) and compares these against the implied probabilities embedded in betting odds. An official pick is only generated when the gap is meaningful. Over the past 30 days: 68.3% win rate across 120 official picks, +13.44 units.
Next step
The US Open 2026 enters its second week with an unusually open field. Our model will be running through every round-of-16, quarterfinal, and semifinal match — official picks are published daily on the tennis page.
To go deeper on our methodology, read our hard court tennis AI guide and our full WTA AI predictions guide.
