# ProbaPredict data studies: 2026-10 press summary

# Our Model vs the Bookmakers: 18,807 Matches Tested

**Closing odds were 2.8% more accurate than our model across 18,807 matches.**

## Key numbers
- Gap (%, positive = closing odds more accurate): 2.77
- Over/Under 2.5 gap (%): 2.71
- Disagreements where the market was closer: 62.4%

## Method
Walk-forward back-test: for every week from 2022-23 to 2025-26 we refitted our Dixon-Coles model using only matches played before that Monday, then predicted the week's matches. Closing odds (the market average just before kick-off) were converted to probabilities by dividing each implied probability by the book total (the proportional method), which removes the bookmaker margin. Accuracy is measured with the Brier score (squared error over home, draw and away; lower is better) and log loss.

## Citation
ProbaPredict Data Desk (2026). "Our Model vs the Bookmakers: 18,807 Matches Tested". ProbaPredict. https://probapredict.app/studies/model-vs-bookmakers (accessed 2026-10-02). Licensed CC BY 4.0.

Data: 18,807 matches, 2022-23 to 2025-26. Licence: CC BY 4.0, attribution "Source: ProbaPredict (probapredict.app)". Historical results and closing odds: football-data.co.uk.

# Which Football League Is the Most Predictable?

**The Primeira Liga was the most predictable league; the Championship the least.**

## Key numbers
- Matches analysed: 16,627
- Brier score, most predictable (Primeira Liga): 0.532
- Brier score, least predictable (Championship): 0.622

## Method
For every match with closing odds we converted the home, draw and away prices into probabilities and removed the bookmaker margin with the proportional method. Predictability is the Brier score of those probabilities against the 90-minute result (lower = results closer to expectations). The favourite is the side with the higher probability; an upset is a favourite priced at 60% or more that failed to win. Rankings use completed seasons 2021-22 to 2025-26.

## Citation
ProbaPredict Data Desk (2026). "Which Football League Is the Most Predictable?". ProbaPredict. https://probapredict.app/studies/most-predictable-football-league (accessed 2026-10-02). Licensed CC BY 4.0.

Data: 16,627 matches, 2021-22 to 2025-26. Licence: CC BY 4.0, attribution "Source: ProbaPredict (probapredict.app)". Historical results and closing odds: football-data.co.uk.