Win probability

Sunday, 23 August 2026

10 matches selected · 9 tournaments · model last ran 22:50 UTC

Umpiry rates 10 matches on Sunday, 23 August 2026. The closest is M. Sciahbasi v Iannis Miletich at 52 % — the model’s most uncertain call of the day. The most one-sided is Coco Gauff v Sara Bejlek at 82 %. 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
11:05M15 Arad
ITF · clay
FSciahbasi M.Miletich I.52 %48 %Toss-up1–0
16:05W15 Wanfercee-Baulet
ITF · clay
FAndrienko M.Claeys L.54 %46 %Toss-up1–0
22:00Cincinnati
ATP · hard
SFTiafoe F.Nakashima B.54 %46 %Toss-up7–1
08:00M15 Maanshan 7
ITF · hard
FIsomura K.Rifqi F.54 %46 %Toss-up1–1
11:05W75 Kursumlijska Banja 3
ITF · clay
FEncheva L.Zolotareva R.56 %44 %Toss-up0–1
12:05M25 Lesa
ITF · clay
SFWeis A.Basile P.59 %41 %Slight edge0–1
00:30Cancun 2
CHALLENGER · hard
SFHarris L.Baez S.61 %39 %Slight edge1–1
20:00Quebec City
CHALLENGER · hard
FVan Assche L.Sakellaridis S.62 %38 %Slight edge1–0
23:30Cincinnati
ATP · hard
FFils A.Tiafoe F.68 %32 %Clear favourite2–0
23:30Cincinnati
WTA · hard
SFGauff C.Bejlek S.82 %18 %Strong favourite1–0

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

Saturday, 22 August 2026 · 20 matches

Favourites won

8 / 20

Model expected

11.6

The model expected 11.6 favourites to win; 8 did. See yesterday’s page.

Biggest shock, last 7 days

21 Aug
W35 Erwitte
ITF · clay
QF

Surprise score

92

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.