How to Read OddsAccuracy: OA Score, Rankings & TAI

OA Score & Rankings

OA Score summarizes recent bookmaker probability forecast error into a single comparative measure.

• Rankings are relative within the selected context (window and odds type).
• Small score differences matter more than absolute rank positions.
• Rankings answer “who has been more accurate recently?”, not “who is best forever”.

Opening vs Closing Odds

OddsAccuracy keeps opening and closing OA Scores separate because they represent different points in the bookmaker market process.

• Live opening odds are the bookmaker’s first valid price observed by OddsAccuracy. Observation normally starts seven days before kickoff, and each bookmaker can first appear at a different time. The observation time does not verify the bookmaker’s true market launch.
• Closing odds show the market state nearer kickoff after later information and market adjustment.
• A lower closing OA Score than opening OA Score indicates that closing prices were more accurate over that sample; the reverse can also occur.

Captures near the collection start may already reflect a market opened earlier. A delayed collection start can also miss earlier prices. Historical reconstructed openings are separate snapshots, typically at T−72h; they do not establish live opening timing. Earlier prices can legitimately change as information arrives. An API quote alone does not establish stake acceptance, limits or liquidity. Inspect observation times and collection-start indicators.

Do not assume that closing odds must always be more accurate. Compare the two on the same league, window, and sample.

Predictable / Unpredictable Teams

Both cards offer 10 / 20 / 30 matches, matching the TAI window selector. Each window uses the latest eligible matches involving each team, rather than the latest matches across the whole league. Opening and Closing have independent match samples.

Each match contributes the average of its valid bookmaker OA Scores; the card averages those match scores over the selected team window. Predictable Teams list the lowest averages first; Unpredictable Teams list the highest averages first. These labels describe past alignment with market probabilities. They do not predict future results or recommend bets.

Standard OAMS rankings require at least 30 matches. The 10- and 20-match descriptive views do not meet that requirement. In available-data mode, fewer eligible matches may be used when a full window is unavailable; selecting 30 alone does not establish standard eligibility. Shorter samples are more volatile.

Team Accuracy Index (TAI)

TAI focuses on team-specific behavior and highlights where pricing deviates systematically for specific teams.

Lower windows may show sharp swings — this is expected and reflects short-term volatility, not instability.

TAI Analyst

The TAI Analyst summarizes observable signals such as:

Learn More About OddsAccuracy

• Methodology: how OA Score and bookmaker odds accuracy are calculated
• What Is a Brier Score?
• How Accurate Are Football Odds?
• How to Measure Prediction Accuracy in Football
• Browse all OddsAccuracy Research