Win probability

Sunday, 9 August 2026

17 matches selected · 11 tournaments · model last ran 17:50 UTC

Umpiry rates 17 matches on Sunday, 9 August 2026. The closest is Ella Mcdonald v Amelia Rajecki at 50 % — the model’s most uncertain call of the day. The most one-sided is Aryna Sabalenka v Ekaterina Alexandrova 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
09:40W35 Roehampton
ITF · hard
FMcdonald E.Rajecki A.50 %50 %Toss-up0–1
11:10Grodzisk Mazowiecki
CHALLENGER · hard
FGuerrieri A.Schwaerzler J.51 %49 %Toss-up1–1
13:20W75 Koksijde
ITF · clay
FBasiletti N.Palicova B.51 %49 %Toss-up1–0
01:55Toronto
WTA · hard
R16Svitolina E.Anisimova A.52 %48 %Toss-up5–1
16:45Montreal
ATP · hard
R16Griekspoor T.Merida Aguilar D.53 %47 %Toss-up0–1
12:35Hagen
CHALLENGER · clay
FKym J.Gentzsch T.53 %47 %Toss-up1–2
00:25Montreal
ATP · hard
R16Lehecka J.Jodar R.54 %46 %Toss-up0–1
17:10Lexington
CHALLENGER · hard
FButvilas E.Ilagan A.56 %44 %Toss-up1–1
13:00M15 Eupen
ITF · clay
FPapamalamis T.Van Der Meerschen M.57 %43 %Toss-up0–1
08:40W75 Ourense
ITF · hard
FZhiyenbayeva S.Shinikova I.57 %43 %Toss-up1–0
16:10Istanbul 2
CHALLENGER · hard
FSimakin I.Poullain L.57 %43 %Toss-up0–1
16:15W100 Landisville
ITF · hard
FZakharova A.Vandewinkel H.64 %36 %Slight edge0–2
18:15Montreal
ATP · hard
R16Tien L.Tirante T.73 %27 %Clear favourite1–0
02:00Montreal
ATP · hard
R16Fils A.Norrie C.77 %23 %Clear favourite1–0
19:50Toronto
WTA · hard
R16Gauff C.Korneeva A.79 %21 %Clear favourite1–0
16:40Toronto
WTA · hard
R16Rybakina E.Samsonova L.84 %16 %Strong favourite3–4
23:10Toronto
WTA · hard
R16Sabalenka A.Alexandrova E.92 %8 %Strong favourite5–5

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, 8 August 2026 · 20 matches

Favourites won

13 / 20

Model expected

11.9

The model expected 11.9 favourites to win; 13 did. See yesterday’s page.

Biggest shock, last 7 days

7 Aug
M15 Astana 2
ITF · hard
R16

Surprise score

89

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.