How accurate are the WTA US Open odds?
The closing prices of 946 finished games since Tue 24 Aug 2021, set against what happened: the chance the market gave, with the bookmakers' margin removed, next to how often it came in. A record of what the market did, not a tip.
The market's record
946 games, 2 bookmakers- Closing favourite won 72% 677 of 946 games
- Market Brier score 0.367 0 is perfect; a coin flip scores 0.500
- Average closing payout 94.4% 100% minus the bookmakers' margin
- Games covered 946 Tue 24 Aug 2021 to Sat 6 Sep 2025
14 of the 960 games finished in that time are left out: no bookmaker had a closing price on every outcome.
Market chance against what happened
| Market chance | Price | Selections | Market said | Happened | Diff |
|---|---|---|---|---|---|
| 0-10% | 10.00 or longer | 60 | 7.1% | 5.0% | -2.1 pts |
| 10-20% | 5.00 to 10.00 | 171 | 15.5% | 9.9% | -5.6 pts |
| 20-30% | 3.33 to 5.00 | 204 | 25.4% | 24.0% | -1.4 pts |
| 30-40% | 2.50 to 3.33 | 240 | 35.1% | 30.4% | -4.7 pts |
| 40-50% | 2.00 to 2.50 | 270 | 44.7% | 46.7% | +2.0 pts |
| 50-60% | 1.67 to 2.00 | 272 | 55.3% | 53.3% | -2.0 pts |
| 60-70% | 1.43 to 1.67 | 240 | 64.9% | 69.6% | +4.7 pts |
| 70-80% | 1.25 to 1.43 | 204 | 74.6% | 76.0% | +1.4 pts |
| 80-90% | 1.11 to 1.25 | 171 | 84.5% | 90.1% | +5.6 pts |
| 90-100% | 1.11 or shorter | 60 | 92.9% | 95.0% | +2.1 pts |
Every priced outcome of every game is one selection. "Market said" is the bookmakers' average implied probability with the margin removed; "Happened" is how often that outcome came in. On the diagonal the market was right on average; above it, that kind of result happened more often than the prices said. Bands with fewer than 30 selections are left out.
Home, away
| Outcome | Market said | Happened | Diff |
|---|---|---|---|
| Home win | 51.3% | 51.0% | -0.3 pts |
| Away win | 48.7% | 49.0% | +0.3 pts |
The market's average closing chance for each outcome over all 946 games against the share of games it won. "Home" is the first-named side.
Bookmaker accuracy
lower is better| Bookmaker | Games | Brier score | vs market average | Payout |
|---|---|---|---|---|
 Unibet |
808 | 0.356 | -0.002 | 94.6% |
 Bet365 |
744 | 0.369 | +0.006 | 94.5% |
Each bookmaker's own closing prices, margin removed, scored against the results of the games it priced; "vs market average" compares it with the bookmakers' average on the same games, so a negative figure means its prices were the closer. Bookmakers with fewer than 50 priced games are left out. Differences of a few thousandths are noise; a much higher score usually means the bookmaker's last price was captured well before the start, so it is the price in our archive being scored, not the trader.
Odds accuracy FAQ
How accurate are WTA US Open odds?
What is a Brier score?
Does a well-calibrated market mean the odds cannot be beaten?
See the league's fixtures, results and the favourites' recent record on the WTA US Open page, every game behind these figures in the WTA US Open results and closing odds by season, or work out a price's implied chance and closing line value with the betting calculators.