Outsiders

Do outsiders win? The reality of backing big prices

Everyone remembers the 25/1 winner. Nobody counts the hundreds that finished down the field. We took every runner sent off bigger than 16/1 and checked how often the outsider actually obliges.

1.5% to 2.1%

Win rate of horses sent off bigger than 16/1, by field size. Backing them all to level stakes loses 39% to 52% at SP.

The bigger the field, the longer the odds against

An outsider in a small field at least has fewer rivals to beat. Pile into a 20-runner handicap and the same price is, if anything, still too short for the real chance.

Field size	Runs	Win rate	ROI at SP
Small (2 to 7)	58,871	2.1%	-39.0%
Medium (8 to 12)	267,246	1.9%	-42.0%
Large (13 to 16)	171,664	1.8%	-44.3%
Huge (17+)	76,892	1.6%	-51.9%

Why outsiders are a trap

The numbers are a textbook case of the favourite-longshot bias: the prices look generous precisely because the chances are tiny and the market knows punters cannot resist them.

Backing outsiders for the thrill is fine if you treat the stake as entertainment. As a strategy it is the most reliable way to lose in racing.

If you do want to play big prices, the only sane way is selectively, where there is a genuine reason the market has the horse too big, not as a blanket bet on every longshot on the card.

See where the model thinks the market is wrong

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 Overlay

Related reading: The favourite-longshot bias · Do favourites win? · all studies.

Method, in plain English

Every settled runner sent off bigger than 16/1 (SP), 2010 to June 2026, grouped by the size of the field. Win rate is wins divided by runs. ROI is level-stakes SP return. Historical and for information only.