Win probability

Friday, 31 July 2026

20 matches selected · 12 tournaments · model last ran 19:50 UTC

Umpiry rates 20 matches on Friday, 31 July 2026. The closest is Mia Ristic v Laura Samson at 51 % — the model’s most uncertain call of the day. The most one-sided is Naomi Osaka v Elisabetta Cocciaretto at 78 %. 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
09:10Targu Mures
CHALLENGER · clay
QFRistic M.Samson L.51 %49 %Toss-up1–1
07:30W15 Astana 3
ITF · hard
QFKorysheva E.Dyussebay I.51 %49 %Toss-up2–0
13:00M25 Bolzano
ITF · clay
SFWeis A.Sorger S.52 %48 %Toss-up0–1
00:00M15 Brisbane 2
ITF · hard
QFHazawa S.Bouzige M.52 %48 %Toss-up0–1
23:40Washington
WTA · hard
R16Shnaider D.Potapova A.53 %47 %Toss-up2–1
12:20W75 Hechingen
ITF · clay
QFTsygourova K.Palicova B.53 %47 %Toss-up0–1
07:30M15 Astana
ITF · hard
QFBrand D.Nurlanuly Z.53 %47 %Toss-up0–1
15:10San Marino
CHALLENGER · clay
QFPoljicak M.Muller A.54 %46 %Toss-up1–0
09:10M25 Gentofte
ITF · clay
QFThanos A.Vasa E.56 %44 %Toss-up0–1
10:45W35 Aldershot
ITF · hard
QFChaudhari V.Klimovicova L.56 %44 %Toss-up0–1
02:10Los Cabos
ATP · hard
QFBrooksby J.Wong C.62 %38 %Slight edge1–1
18:10Washington
ATP · hard
QFDe Minaur A.Nakashima B.64 %36 %Slight edge2–3
01:05Los Cabos
ATP · hard
QFCerundolo F.Gea A.65 %35 %Slight edge0–1
04:10Los Cabos
ATP · hard
QFShapovalov D.Svrcina D.67 %33 %Slight edge1–0
20:40Washington
WTA · hard
QFShnaider D.Samsonova L.67 %33 %Slight edge3–1
20:25Washington
ATP · hard
QFFritz T.Michelsen A.67 %33 %Clear favourite2–2
22:40Washington
ATP · hard
R16Shelton B.Humbert U.68 %32 %Clear favourite2–0
01:30Washington
WTA · hard
R16Svitolina E.Kudermetova P.77 %23 %Clear favourite1–0
16:10Washington
WTA · hard
QFPegula J.Kalinskaya A.77 %23 %Clear favourite5–1
18:10Washington
WTA · hard
QFOsaka N.Cocciaretto E.78 %22 %Clear favourite2–0

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

Thursday, 30 July 2026 · 16 matches

Favourites won

11 / 16

Model expected

10.8

The model expected 10.8 favourites to win; 11 did. See yesterday’s page.

Biggest shock, last 7 days

30 Jul
W15 Bielsko Biala
ITF · clay
R16

Surprise score

86

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.