Definition
Odds-On
Also known as Odds On, Short Price, Under Evens
By Abhinav VasudevanReviewed Editorial policy
In short
An odds-on selection is priced below even money, meaning you stake more than you stand to win. A 1/2 shot requires £20 to win £10, and implies a probability above 50%.
Odds-on describes any price below even money. Decimal under 2.00, a negative American number, or a fraction with the larger figure on the right.
| Price | Stake to win £10 | Implied |
|---|---|---|
| 1/2 | £20 | 66.7% |
| 1/3 | £30 | 75.0% |
| 1/5 | £50 | 83.3% |
| 1/10 | £100 | 90.9% |
Racing convention reverses the spoken order: 1/2 is said “two to one on”, not “one to two”. A commentator saying “he is two to one on” means 1/2, a heavy favourite, the opposite of 2/1.
Why short prices are usually poor value
Two things work against odds-on bets, and they compound.
The margin hurts more proportionally. A bookmaker’s overround is spread across the market, but at short prices it eats a larger share of the available return. Taking 1/5 when the fair price is 1/4 costs you a great deal relative to what you stand to win.
Small mistakes are expensive. At 1/5 you need to win about 83% of the time to break even. One unexpected loss wipes out five wins. There is very little room for the price to be slightly wrong, and it frequently is.
Where they are genuinely used
Odds-on prices are not automatically bad. They are the correct price for likely outcomes. They appear legitimately in three places:
- Accumulator legs, where several short prices multiply into something meaningful.
- Lay betting on an exchange, where laying a 1/5 shot means risking a little to win a lot if it is beaten.
- Hedging, where a short price locks in a position taken earlier at longer odds.
The trap is backing odds-on selections singly because they feel safe. Safety is already in the price, and it has been charged for.
Common questions
What does two to one on mean?
It means 1/2 in fractional odds, so you stake £20 to win £10. Racing convention reverses the spoken order for odds-on prices, which catches people out when they hear it called at a racecourse.
Are odds-on bets bad value?
Often, because margin eats a larger share of the small available return and one unexpected loss wipes out several wins. They are correct prices for likely outcomes, but backing them singly because they feel safe is paying for safety already in the price.