It is the most important pattern in betting and almost nobody prices it in: the longer the odds, the worse the value. Back every runner in a price band and the loss grows steadily as the prices get bigger. We measured it on 1,798,064 settled runners.
| Price band | Runs | Win rate | ROI at SP |
|---|---|---|---|
| Odds-on (evens or shorter) | 37,395 | 58.5% | -3.8% |
| Evens to 2/1 | 88,453 | 36.7% | -4.5% |
| 2/1 to 4/1 | 251,236 | 22.7% | -7.0% |
| 4/1 to 8/1 | 408,301 | 12.7% | -10.8% |
| 8/1 to 16/1 | 438,006 | 6.5% | -16.9% |
| 16/1 to 33/1 | 329,619 | 2.7% | -32.7% |
| Bigger than 33/1 | 245,054 | 0.7% | -58.6% |
The lesson is not 'only back favourites', it is that price alone is never the edge. A 20/1 shot can be a good bet if its true chance is better than 20/1, and a 6/4 shot can be a bad one. The job is to find the gap between true chance and offered price, which is exactly what the model is built to do.
It also explains why chasing big-priced winners feels exciting and drains a bankroll: the rare hit never makes up for the steady losses in between.
The Overlay is a free, data-driven UK and Irish racing model. It looks for the gap between a horse's true chance and its price, logs every selection before the off, and settles in public, win or lose. It is not a tipster, and it tells you when to sit a race out.
Explore The OverlayRelated reading: Do favourites win in horse racing? · Are second favourites good value? · all studies.
Every settled runner in our database from 2010 to June 2026 with a valid starting price (1,798,064 runs). Win rate is wins divided by runs in each band. ROI is level-stakes return at SP: stake 1 point on every runner in the band and measure profit or loss per point. Historical and for information only.