Guide · updated 2026-10-01
Are bookmaker odds accurate?
Bookmakers' closing odds have been more accurate than the model. On 1,141 Premier League matches from 2023-09-23 to 2026-09-20, de-vigged closing odds scored a log loss of 0.969 against 0.991 for our model, where lower is better.
How the test works
The model's settings were chosen and calibrated on earlier seasons, then frozen. It then predicted each later match using only results available before kickoff. The same matches were scored with closing prices from football-data.co.uk (Pinnacle where available, otherwise the market average), with the margin removed as described in our odds guide.
Results
| Measure | Model | Closing odds |
|---|---|---|
| Log loss (lower is better) | 0.991 | 0.969 |
| Brier score (lower is better) | 0.591 | 0.577 |
| Most likely result happened | 51.8% | 53.8% |
The 95% interval for the model's log loss minus the market's, resampling whole weeks, runs from 0.011 to 0.031.
For scale, predicting every match from the league's past home, draw and away rates scored 1.077, and picking the favourite of those rates was right 42.9% of the time.
What this means
Even the best prices only pick the most likely result about half the time, because football is low-scoring and random. Accuracy is about well-sized probabilities, not calling winners. A gap between a model and the market is therefore not, on its own, a reason to think the market is wrong.
See the model record for calibration and the live record of predictions published before kickoff.
Common questions
How do you measure whether odds are accurate?
Score the probabilities against what happened. Log loss takes minus the log of the probability given to the actual result, averaged over matches; the Brier score averages the squared errors. Lower is better for both.
Why use closing odds?
Closing prices are set just before kickoff, after team news and the most betting. They are usually the market's most informed estimate, which makes them the hardest benchmark.
Did the model beat the closing odds?
Bookmakers' closing odds have been more accurate than the model: on 1,141 held-out matches the model's log loss was 0.991 and closing prices scored 0.969.
More guides
Probabilities are not guarantees and nothing here is betting advice. Responsible gambling.