Ante-post betting
An ante-post bet is a bet struck at a fixed price before the final declarations for an event, often weeks or months before it takes place. You usually get a bigger price than on the day, and the trade-off is that a standard ante-post bet is settled as a loser if your selection does not take part. That single rule shapes everything else about the market, from the odds on offer to the concessions bookmakers use to win your business.
Why the early price is bigger
The bookmaker is pricing in uncertainty you agree to carry. A horse at 10/1 ante-post implies a probability of 1 in 11, about 9.1%, and part of that low figure reflects the chance it never reaches the start at all.
Injury, a change of target or unsuitable ground can each rule a horse out, and on standard terms the stake is gone.
How Rule 4 and non-runners are treated
Ante-post bets are generally exempt from Tattersalls Rule 4(c), which cuts winnings on day-of-race prices when a rival is withdrawn. If the favourite drops out, your price stands.
The same logic works against you when your own horse is the one withdrawn. Bookmakers word the exemption as “generally”, with exceptions set out in their own rules, so the terms of the bet decide it.
Each-way follows the same non-runner rule, so a fiver each way on a horse that never runs costs you a tenner.
Ante-post versus non-runner no bet
Non-runner no bet, sometimes labelled NRMB, is a bookmaker concession that voids the bet and refunds the stake if your selection does not run. It is commonly offered on big festivals such as Cheltenham, but coverage of races varies between operators.
The protection only applies in a market clearly marked NRNB. Once final declarations are made, usually around 48 hours before a race, betting moves to day-of-race terms, where a non-runner returns your stake and Rule 4 may apply.
