Win probability

Tuesday, 8 September 2026

15 matches selected · 8 tournaments · model last ran 17:50 UTC

Umpiry rates 15 matches on Tuesday, 8 September 2026. The closest is Max Hans Rehberg v Thiago Monteiro at 50 % — the model’s most uncertain call of the day. The most one-sided is Alexander Zverev v Luciano Darderi at 93 %. Probabilities come from a per-tour model trained on Elo, surface Elo, recent serve and return form and layoff.

Rated matches · ordered closest first
TimeTournamentRoundMatchProbabilityVerdictH2H
16:35Tulln
CHALLENGER · clay
R32Hans Rehberg M.Monteiro T.50 %50 %Toss-up0–1
12:30Tulln
CHALLENGER · clay
R32La Serna J.Jianu F.50 %50 %Toss-up1–0
20:00US Open
ATP · hard
QFTiafoe F.Michelsen A.51 %49 %Toss-up3–0
11:00W35 Reus
CHALLENGER · clay
R32Torner Sensano N.Cherubini D.51 %49 %Toss-up0–1
13:30Montreux Nestle Open - Montreux
CHALLENGER · clay
R32Havlickova L.Radivojevic L.52 %48 %Toss-up2–0
10:00Shanghai
CHALLENGER · hard
R32Kotov P.Ymer E.53 %47 %Toss-up2–2
14:00Cassis
CHALLENGER · hard
R32Ghazouani Durand Y.Janvier M.55 %45 %Toss-up1–1
15:45Montreux Nestle Open - Montreux
CHALLENGER · clay
R32Maristany Zuleta De Reales G.Bassols Ribera M.55 %45 %Toss-up3–2
15:20Istanbul
CHALLENGER · hard
R32Erel Y.Skatov T.56 %44 %Toss-up1–0
14:55Tulln
CHALLENGER · clay
R32Brunold M.Damas M.56 %44 %Toss-up2–3
11:30Shanghai
CHALLENGER · hard
R32Wei Kang Leong M.Jasika O.56 %44 %Toss-up0–1
17:25Montreux Nestle Open - Montreux
CHALLENGER · clay
R32Masarova R.Waltert S.57 %43 %Toss-up1–2
02:00US Open
WTA · hard
R16Gauff C.Jovic I.72 %28 %Clear favourite2–0
18:30US Open
WTA · hard
QFSabalenka A.Noskova L.79 %21 %Clear favourite3–0
03:30US Open
ATP · hard
R16Zverev A.Darderi L.93 %7 %Strong favourite2–1

How to read this

Each row gives the model’s probability that the favourite wins, and the verdict says the same thing in words. Rows are ordered by how close the model thinks the match is, so the top of the table is where it is least sure. A 70 % favourite losing is not a broken model — it is the 30 %. Probabilities are not odds and take no account of any market.

How often the model has been right

Umpiry win-probability model accuracy by tour family, measured on the predictions the model made
TourCorrect
ATP / WTA66 %
Challenger (men)64 %
Challenger (women)68 %
ITF (men)66 %
ITF (women)64 %

Measured on the predictions the model actually made, not on a backtest — see Methodology.

Yesterday

Monday, 7 September 2026 · 15 matches

Favourites won

8 / 15

Model expected

9.1

The model expected 9.1 favourites to win; 8 did. See yesterday’s page.

Biggest shock, last 7 days

7 Sept
M25 Gijon
ITF · clay
Q16

Surprise score

82

Questions

How is the probability calculated?
A separate model for each tour, trained on Elo, surface-specific Elo, recent serve and return form and time since the player’s last match. It runs several times a day; the time of the last run is at the top of this page.
How often is the model right?
We publish it. The table above gives the hit rate for each tour family, measured on the predictions the model actually made — see Methodology for how it is computed.
Why are the closest matches at the top?
Rows are ordered by distance from 50 %, so the table opens where the model is least sure. “Most one-sided” reverses the order and groups the rows by tournament.
Is this a betting tip?
No. The page shows a model’s probability and how often that model has been right. There are no odds, no comparison with a market and no suggested stake.