Ante-Post Betting Explained: Non-Runners, NRNB and the Maths

An ante-post bet is a bet on a horse race placed before the final declarations, the point a day or two before the race when trainers confirm which horses will actually take part. Prices for the biggest races in Britain and Ireland go up weeks or months in advance: the Cheltenham Festival in March, the Grand National in April, the Derby at Epsom and Royal Ascot in June. Some markets open as soon as the previous year's race is over.

Pick the right horse early and you can get a price that will never be available again. The cost: if the horse does not run, your stake is usually gone. This page explains how ante-post betting works, how non-runner no bet concessions change the deal, and how to work out whether an early price is worth the risk. If you are new to racing bets, our horse racing betting guide covers the basic bet types first.

How ante-post betting works

Before a big race, horses are entered, often months ahead, then stay in through a series of forfeit stages where owners decide whether to keep paying. Finally, usually a day or two before the race, trainers make the final declarations and the runners are fixed. Any bet struck before that last step is ante-post. Bookmakers price the race on every possible runner, which might be thirty or forty horses for a field of twelve. Many will go elsewhere, get injured or find the ground unsuitable.

The traditional rule for these bets is all in, run or not. If the horse wins, you are paid at the price you took. If it loses, or never runs at all, the bet is a loser. The common exception is a race that is abandoned, where bookmakers usually void ante-post bets and return stakes under their own terms.

Why ante-post prices are bigger

Early prices are bigger for two reasons. The first is non-runner risk: the bookmaker keeps your stake if the horse does not turn up, and part of the bigger price is payment for that. The second is uncertainty. Months out, nobody knows the going, the final field, the jockey or how the horse will come through its preparation races. If you read a trainer's plans or a horse's form correctly before the market does, you get paid for being early.

A horse at 10/1 (11.0 in decimal odds) in January can be 5/1 (6.0) on the morning of the race if it wins its trial and gets its preferred ground. It can also drift to 25/1 or miss the race altogether. The bigger price is the market's charge for everything that can still go wrong.

Non-runners: the main risk and how NRNB changes it

On race day, a fixed-odds bet on a horse that is withdrawn is void and the stake comes back. Ante-post, a non-runner is a loser with no refund. In return, bets placed before the final declarations are normally not subject to Rule 4, because you accepted the risk of your own horse not running. Our page on Rule 4 deductions explains how those deductions work on bets placed after declarations.

For the big meetings, many bookmakers offer non-runner no bet (NRNB) on selected races: if your horse does not run, the stake is returned. Check three things every time:

• When the concession starts. It varies by bookmaker and by race. For the Cheltenham Festival it is often offered from a few weeks before, sometimes earlier, sometimes only for certain races. Bets struck before the concession began are not covered.
• Whether the NRNB price is smaller. A bookmaker may offer 12/1 all in, run or not, and 9/1 NRNB on the same horse at the same time.
• Whether Rule 4 applies. Some bookmakers apply Rule 4 deductions to NRNB bets when other horses come out. Read the terms.

Best odds guaranteed is a separate concession and usually applies only to bets placed on the day of the race, not to ante-post bets. See our guide to best odds guaranteed for how it works and where it stops.

Each-way ante-post bets and place terms

Big festival races have large fields and long prices, so each-way betting is common ante-post. An each-way bet is two equal bets, one to win and one to place, with the place part paid at a fraction of the win odds, typically 1/4 or 1/5, though terms vary by bookmaker and field size. Our guide to each-way bets covers the terms in detail.

Take £5 each-way at 20/1 (21.0) with place terms of 1/5 the odds for four places. The total stake is £10.

• If the horse wins, the win part returns £5 x 21 = £105 and the place part returns £5 at 4/1, which is £25. Total return £130.
• If it finishes third, the win part loses and the place part returns £25. You get £25 back from £10.
• If it does not run and the bet was not NRNB, both parts lose. You lose £10.

The place terms you get are the ones stated when you placed the bet, but a race that ends up with a small final field can be settled differently, depending on the bookmaker's rules. Extra-place offers for races like the Grand National are often announced close to the race, so an early each-way bet may not get them. The Grand National betting guide shows how place terms work in a forty-runner field.

How ante-post prices move

Ante-post markets move on news more than on money. The main triggers:

• Entries and forfeit stages. Paying to stay in a race signals intent; when a fancied horse drops out, the others shorten.
• Trainer and jockey comments. A trainer naming the target race, or a top jockey choosing one ride over another, often moves the price sharply.
• Trials and setbacks. A good run in a recognised trial shortens a horse; a poor one or a training setback lengthens it.
• The going. A horse that needs soft ground may not run if the spring is dry, and the reverse.
• Weights and declarations. Published handicap weights reshape the market, and once the field is known the non-runner risk disappears and prices tend to tighten.

Early prices move in jumps. A horse can sit at 16/1 for weeks and be 6/1 the morning after its trainer confirms the plan.

Ante-post versus race-day prices: the maths

To compare an early price with a race-day price, multiply the decimal ante-post odds by your estimate of the chance the horse runs. The result is the race-day decimal price the ante-post bet is worth.

Suppose a horse is 10/1 (11.0) ante-post, all in, run or not. You think there is a 70% chance it makes the line-up. If it runs, you expect it to be around 5/1 (6.0) on the day.

• Effective ante-post price: 11.0 x 0.70 = 7.70, roughly 6.7/1.
• Break-even win chance with the ante-post bet, assuming it runs: 1 / 7.70 = 13.0%.
• Break-even win chance at 5/1 on the day: 1 / 6.0 = 16.7%.

So in this example the ante-post bet needs a lower win probability to break even, and it is the better bet. Put £10 on in each case and assume the horse has a 15% chance of winning if it runs. The ante-post bet returns £110 if it wins, so its expected value is 0.70 x 0.15 x £110 minus £10, which is +£1.55. The race-day bet at 5/1 returns £60 if it wins, so its expected value when you place it is 0.15 x £60 minus £10, which is minus £1.00.

If the horse ends up 8/1 (9.0) on the day instead, the break-even chance is 11.1%, lower than 13.0%, so waiting would have been better. The run probability matters as much as the price. At 10/1 ante-post against 5/1 on the day, the two bets are equal when the run chance is 6.0 / 11.0, about 54.5%. Below that, the early price is worse even though it looks twice as big.

With NRNB the run probability effectively becomes 100%, because a non-runner returns your stake. That is why a 10/1 NRNB price is worth a lot more than a 10/1 run-or-not price on the same horse.

Ante-post bets in other sports

UK bookmakers also use ante post, or outright, for long-range bets in other sports: the Premier League winner or top goalscorer before a ball is kicked, or a golf major months ahead, often bet each-way. In football outrights the team always takes part, so the risk is form and injuries rather than turning up. In golf, rules on players who withdraw before teeing off vary between bookmakers and between long-range and pre-tournament markets, so check them. Our article on futures betting covers outrights across sports, including how to measure the margin built into an outright board.

Hedging or laying an ante-post bet

If your horse shortens a lot, you can lock in profit with a lay bet on a betting exchange, where you bet against the horse winning. Some bookmakers offer cash out on ante-post bets, usually at a worse price than you could build yourself. Our guide to hedging and cash out compares the two.

Say you backed a horse at 20/1 (21.0) for £10, all in, run or not. It has been declared and is now 4/1 (5.0) to lay on an exchange. To make the same profit whatever happens, divide the potential return by the lay odds: £10 x 21.0 / 5.0 = £42 lay stake. Your liability on the lay is £42 x (5.0 minus 1) = £168.

• If the horse wins: +£200 from the bookmaker bet, minus £168 on the lay, a profit of £32.
• If the horse loses: minus £10 on the bookmaker bet, plus £42 from the lay, a profit of £32 before commission. With 5% commission on the £42 it is £29.90.

Lay only once the horse is declared, or read the exchange's non-runner rules for that market first. If the horse comes out and your bookmaker bet loses while the lay settles differently, the hedge can leave you worse off. A partial lay that keeps some upside is common, and you do not have to hedge at all.

Before you place an ante-post bet

Run through this list before you confirm:

• Check whether the bet is all in, run or not, or non-runner no bet, and if NRNB, from what date.
• Compare the NRNB price with the run-or-not price on the same horse.
• Estimate the chance the horse runs in this race, not just that it stays sound. Trainers often split several entries across different races.
• Multiply the decimal price by that chance and compare it with what you expect on the day.
• For each-way bets, read the place terms and know what happens if the field shrinks.
• Write down the date, price, stake and terms. Ante-post bets sit in an account for months and are easy to forget.
• Treat the stake as spent until the race is run.

Betting law differs by country and, in the US, by state, and online betting is prohibited in India. Use a licensed operator where you live. If long-range bets start to feel like a way to chase earlier losses, set limits or take a break, and see our responsible gambling page for help.