Market bias
Favourite-longshot bias in football odds
A practical check on long 1X2 prices, draw buckets and totals buckets using imported Football-Data history.
Updated 2026-05-11 18:09 UTC. Paper-trading research only.
Favourite-longshot bias check from imported football-data history. ROI is from blindly backing every selection in the bucket at the recorded maximum price, so this is a diagnostic rather than a betting system.
1X2
| Selection | Odds bucket | Bets | Strike | Avg odds | ROI |
|---|---|---|---|---|---|
| AWAY_WIN | <1.50 | 820 | 74.0% | 1.36 | 0.0% |
| AWAY_WIN | 1.50-1.99 | 2665 | 57.1% | 1.77 | 0.7% |
| AWAY_WIN | 2.00-2.99 | 10459 | 40.3% | 2.52 | 0.3% |
| AWAY_WIN | 3.00-3.99 | 9783 | 27.8% | 3.43 | -5.1% |
| AWAY_WIN | 4.00-5.99 | 8303 | 20.3% | 4.73 | -5.2% |
| AWAY_WIN | 6.00+ | 5180 | 11.4% | 9.55 | -6.7% |
| DRAW | 2.00-2.99 | 322 | 34.5% | 2.91 | -0.2% |
| DRAW | 3.00-3.99 | 27016 | 28.7% | 3.50 | 0.1% |
| DRAW | 4.00-5.99 | 8218 | 22.1% | 4.53 | -1.2% |
| DRAW | 6.00+ | 1749 | 12.8% | 7.97 | -5.4% |
| HOME_WIN | <1.50 | 2840 | 76.5% | 1.33 | 1.3% |
| HOME_WIN | 1.50-1.99 | 8493 | 57.3% | 1.76 | 0.2% |
| HOME_WIN | 2.00-2.99 | 16515 | 40.8% | 2.42 | -2.8% |
| HOME_WIN | 3.00-3.99 | 5497 | 29.1% | 3.37 | -2.8% |
| HOME_WIN | 4.00-5.99 | 2574 | 21.0% | 4.69 | -2.3% |
| HOME_WIN | 6.00+ | 1382 | 10.8% | 9.06 | -6.2% |
Over/Under 2.5
| Selection | Odds bucket | Bets | Strike | Avg odds | ROI |
|---|---|---|---|---|---|
| OVER | <1.70 | 6304 | 64.5% | 1.54 | -0.9% |
| OVER | 1.70-1.89 | 6809 | 56.5% | 1.80 | 1.5% |
| OVER | 1.90-2.09 | 8318 | 49.3% | 1.99 | -1.7% |
| OVER | 2.10-2.39 | 10492 | 43.4% | 2.22 | -3.8% |
| OVER | 2.40+ | 5381 | 37.3% | 2.62 | -2.6% |
| UNDER | <1.70 | 7290 | 61.6% | 1.59 | -2.1% |
| UNDER | 1.70-1.89 | 10609 | 55.5% | 1.79 | -0.6% |
| UNDER | 1.90-2.09 | 7714 | 49.4% | 1.98 | -2.2% |
| UNDER | 2.10-2.39 | 6339 | 42.4% | 2.22 | -5.7% |
| UNDER | 2.40+ | 5352 | 34.6% | 2.84 | -4.2% |
Operating Rule
- Treat long 1X2 prices as contaminated by favourite-longshot bias and bookmaker/outlier noise.
- Prefer two-way markets such as over/under 2.5 for automatic publication until Asian handicap history is available.
- Asian handicap should be researched next, but this data source does not include historical handicap lines, so it needs a dedicated odds-history feed before public automation.
Raw report: market-bias-report.md. Machine-readable data: market-bias-report.json.