Updated September 10, 2026
Coco Gauff and Elena Rybakina meet Thursday night in a US Open semifinal that is expected to be a battle. Gauff enters as the No. 4 seed, the 2023 champion in New York and this year's Cincinnati winner, while Rybakina has just secured the world's No. 1 ranking after beating Qinwen Zheng in the quarterfinals. Both survived difficult three-set matches Wednesday, and we could be in for another three-set match here as well with a spot in the final on the line.
Why Our Model Sees Value:
“Polymarket is pricing this close to a coin flip, but Rybakina’s serve-plus-first-ball combination, recent 3-set victory over Gauff, and ability to attack the American’s forehand give her a matchup edge that is larger than the current price suggests.”
Coin-Flip Pricing
Polymarket currently has Rybakina around 50¢, implying roughly a 50% chance of winning, while Gauff is around 51¢. The market is still relatively young, with roughly $6,400 in reported volume at the time of the latest update. My projection moves Rybakina to 55%, creating a 5% edge at a 50¢ entry point.
Can Rybakina Overcome Hostile Environment?
There is an obvious case for Gauff being favored in New York. She owns the crowd advantage, won Cincinnati immediately before the US Open, and reached the quarterfinals having won 20 consecutive sets. She also showed exceptional composure against Mirra Andreeva, saving 2 match points before winning in 3 sets. Still, Rybakina has the type of weapons that can prevent Gauff from settling into the defensive patterns that have carried her through much of this tournament.
Recommended Prediction:
Rybakina to Win
Current Market Price:
50¢
Model Win Probability:
55%
Market-Implied Probability:
50%
Model Edge:
5%
Buy Up To:
58¢
Model Trade Confidence:
80/100
Gauff and Rybakina are tied 1-1 in their career head-to-head completed matches, with both meetings taking place on outdoor hard courts. Gauff won their first encounter in Toronto in 2022, surviving a long 3-set match 6-4, 6-7(8), 7-6(3). Their second meeting came in the Toronto semifinals in August, where Rybakina reversed the matchup after dropping the opening set and won 5-7, 6-2, 6-2.
That latest result gives a recent picture of how their current games interact. Once Rybakina began shortening rallies and controlling points behind her serve, Gauff had fewer opportunities to use her speed and defensive coverage. Winning the final 2 sets, 6-2, 6-2, was a significant swing after Gauff had taken the opener.
Gauff has been one of the best players of the North American hard-court stretch. She won Cincinnati and carried that form into New York, where she reached the quarterfinals without dropping a set. Her 6-1, 6-4 win over Iva Jovic extended her run to 20 consecutive sets won before Andreeva finally ended that streak Wednesday.
The Andreeva match also exposed the part of Gauff’s game that Rybakina will try to pressure. Gauff opened poorly, committed several forehand errors and hit 5 double faults through her first 2 service games of the second set. She eventually corrected those issues, finishing the deciding set without a double fault and with just 2 unforced errors. That recovery was impressive, but Rybakina is likely to punish a similar slow opening more severely.
Rybakina's 3-6, 6-1, 6-4 quarterfinal win over Zheng guaranteed that she will become the new world No. 1 after the US Open. She struck 20 winners in the match and controlled the middle portion after a difficult opening set.
There had been fitness questions surrounding Rybakina after an injury issue in Cincinnati, to the point that she was uncertain about playing the US Open. Those concerns have faded. She won every match before the quarterfinal in straight sets, including a fourth-round victory over 2-time US Open champion Naomi Osaka.
Rybakina does not need to grind through long rallies to be effective. When she is landing her first serve and hitting the next ball cleanly, she can remove much of an opponent’s defensive advantage.
This is the matchup that could decide the semifinal. Gauff is an elite mover and one of the best defensive players on tour, but Rybakina is built to shorten points. Her first serve can create immediate openings, and she is comfortable stepping inside the baseline on the next ball rather than allowing the rally to reset.
Gauff’s return quality means Rybakina will still have to earn her service holds. The key is what happens after the return lands. If Gauff can consistently put the ball deep through the middle and force Rybakina to hit an extra shot, the American can turn service games into physical contests. If those returns sit short, Rybakina should dictate quickly.
Rybakina should also be aggressive against Gauff’s second serve. Gauff’s serve has improved considerably this summer, and she won 64% of second-serve points in her opening US Open match, but the double-fault problem briefly resurfaced against Andreeva.
Rybakina has the return position and groundstroke pace to make second serves uncomfortable. She can also direct early balls into Gauff’s forehand, which remains the wing opponents most frequently test. Andreeva used that pattern effectively during the first set Wednesday before Gauff stabilized. And that could help make the difference, as we have taken a position on Rybakina here.
