Win probability

Saturday, 5 September 2026

20 matches selected · 7 tournaments · model last ran 01:50 UTC

Umpiry rates 20 matches on Saturday, 5 September 2026. The closest is Qian Sun v Colin Sinclair at 50 % — the model’s most uncertain call of the day. The most one-sided is Elena Rybakina v Yuliia Starodubtseva at 92 %. 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
05:00M15 Wuning
ITF · hard
SFSun Q.Sinclair C.50 %50 %Toss-up1–0
12:55Porto
CHALLENGER · clay
SFVives Marcos P.Dellien H.50 %50 %Toss-up0–1
06:35W75 Tianjin
ITF · hard
SFBai Z.Garland J.55 %45 %Toss-up0–1
05:00W15 Yeongwol
ITF · hard
SFYodpetch K.Sawashiro K.55 %45 %Toss-up1–1
22:10US Open
ATP · hard
R32Gea A.Zheng M.56 %44 %Toss-up3–0
04:00M25 Urayasu
ITF · hard
SFNakagawa N.Yi Lee K.58 %42 %Toss-up1–0
02:00US Open
ATP · hard
R32Tiafoe F.Vacherot V.58 %42 %Slight edge1–0
19:30US Open
ATP · hard
R32Cobolli F.Blockx A.59 %41 %Slight edge1–2
22:00US Open
ATP · hard
R32Darderi L.Sweeny D.60 %40 %Slight edge3–0
21:30US Open
ATP · hard
R32Khachanov K.Bonzi B.60 %40 %Slight edge4–0
18:00US Open
WTA · hard
R32Keys M.Zheng Q.62 %38 %Slight edge1–2
00:20US Open
ATP · hard
R32Lehecka J.Tsitsipas S.66 %34 %Slight edge2–3
04:00US Open
WTA · hard
R32Svitolina E.Kalinskaya A.70 %30 %Clear favourite4–2
18:30US Open
ATP · hard
R32Fritz T.Cerundolo F.71 %29 %Clear favourite1–2
18:00US Open
WTA · hard
R32Anisimova A.Potapova A.75 %25 %Clear favourite2–1
04:10US Open
ATP · hard
R32Shelton B.Shapovalov D.78 %22 %Clear favourite5–0
19:30US Open
WTA · hard
R32Andreeva M.Bartunkova N.81 %19 %Strong favourite1–0
19:30US Open
WTA · hard
R32Swiatek I.Bouzkova M.82 %18 %Strong favourite4–0
22:30US Open
WTA · hard
R32Gauff C.Bucsa C.92 %8 %Strong favourite2–0
02:10US Open
WTA · hard
R32Rybakina E.Starodubtseva Y.92 %8 %Strong favourite1–1

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

Friday, 4 September 2026 · 20 matches

Favourites won

15 / 20

Model expected

14.9

The model expected 14.9 favourites to win; 15 did. See yesterday’s page.

Biggest shock, last 7 days

4 Sept
W50 Leiria
ITF · hard
QF

Surprise score

91

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.