Win probability

Thursday, 20 August 2026

20 matches selected · 7 tournaments · model last ran 19:50 UTC

Umpiry rates 20 matches on Thursday, 20 August 2026. The closest is Gauthier Onclin v Vit Kopriva at 51 % — the model’s most uncertain call of the day. The most one-sided is Madison Keys v Xiyu Wang at 95 %. 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
21:10Cancun 2
CHALLENGER · hard
R16Onclin G.Kopriva V.51 %49 %Toss-up1–1
14:30Prague
CHALLENGER · clay
QFMrva M.Kumstat J.51 %49 %Toss-up1–1
01:40Cancun 2
CHALLENGER · hard
R32Meligeni Alves F.Kouame M.54 %46 %Toss-up0–1
23:25Cancun 2
CHALLENGER · hard
R32Mejia N.Ugo Carabelli C.54 %46 %Toss-up1–3
22:45Cancun 2
CHALLENGER · hard
R32Pacheco Mendez R.Barrios Vera T.54 %46 %Toss-up1–0
09:05Sion
CHALLENGER · clay
QFCompagnucci T.La Serna J.55 %45 %Toss-up1–0
12:00Sion
CHALLENGER · clay
QFKuzmanov D.Giustino L.55 %45 %Toss-up3–3
12:00Prague
CHALLENGER · clay
QFKrutykh O.Hsin Tseng C.56 %44 %Toss-up0–3
01:15Cincinnati
ATP · hard
R16Auger Aliassime F.Tiafoe F.58 %42 %Toss-up3–2
17:10Cincinnati
WTA · hard
QFPegula J.Anisimova A.59 %41 %Slight edge7–0
22:35Cincinnati
ATP · hard
R16Nakashima B.Borges N.59 %41 %Slight edge1–0
13:40Roehampton
CHALLENGER · hard
QFPoullain L.Geerts M.61 %39 %Slight edge2–0
20:20Quebec City
CHALLENGER · hard
R16Popyrin A.Gaston H.62 %38 %Slight edge0–2
12:50Prague
CHALLENGER · clay
QFHans Rehberg M.Jianu F.64 %36 %Slight edge1–1
19:45Cincinnati
ATP · hard
QFPaul T.Cobolli F.65 %35 %Slight edge0–2
01:15Cincinnati
ATP · hard
R16Musetti L.Faria J.71 %29 %Clear favourite1–0
22:35Cincinnati
WTA · hard
R16Gauff C.Bouzkova M.81 %19 %Strong favourite2–2
00:35Cincinnati
ATP · hard
R16Fritz T.O'Connell C.88 %12 %Strong favourite2–0
02:10Cincinnati
WTA · hard
R16Sabalenka A.Bejlek S.91 %9 %Strong favourite0–1
23:10Cincinnati
WTA · hard
R16Keys M.Wang X.95 %5 %Strong favourite3–0

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

Wednesday, 19 August 2026 · 20 matches

Favourites won

8 / 20

Model expected

12.9

The model expected 12.9 favourites to win; 8 did. See yesterday’s page.

Biggest shock, last 7 days

19 Aug
M15 Mistelbach
ITF · clay
R32

Surprise score

93

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.