Betting guide
Rule 4 deductions: why a winner pays short, and by how much
You backed the winner at 3/1, but the bookmaker paid less than you expected. Look at the bet settlement and you will probably see two words: Rule 4. It is the most common reason a winning bet pays short, and it is not a bookmaker trick. It is an industry rule that protects the odds when a horse is withdrawn at the last minute.
What is Rule 4, and why does it exist?
Prices are set for a race with a certain number of runners. If the favourite is withdrawn at the start, every other horse now has a better chance of winning — but your bet was struck at a price that assumed the favourite was running. Rule 4 adjusts winning bets to reflect the stronger position you were left in.
It applies when a horse is withdrawn after you placed your bet and before the race starts — refusing to enter the stalls, getting loose, or being withdrawn by the vet — and there is no time to form a new betting market. It comes from Tattersalls’ Rules on Betting, the standard rules British bookmakers settle by.
Rule 4 deduction table: from 5p to 90p in the pound
The deduction depends on the withdrawn horse’s price when you placed your bet. The shorter its price, the bigger the deduction — because the more likely it was to win, the more your chances improved when it went out.
| Withdrawn horse’s price | Deduction per £1 of winnings |
|---|---|
| 1/9 or shorter | 90p |
| 2/11 to 2/17 | 85p |
| 1/4 to 1/5 | 80p |
| 3/10 to 2/7 | 75p |
| 2/5 to 1/3 | 70p |
| 8/15 to 4/9 | 65p |
| 8/13 to 4/7 | 60p |
| 4/5 to 4/6 | 55p |
| 20/21 to 5/6 | 50p |
| Evens to 6/5 | 45p |
| 5/4 to 6/4 | 40p |
| 8/5 to 7/4 | 35p |
| 9/5 to 9/4 | 30p |
| 12/5 to 3/1 | 25p |
| 16/5 to 4/1 | 20p |
| 9/2 to 11/2 | 15p |
| 6/1 to 9/1 | 10p |
| 10/1 to 14/1 | 5p |
| Bigger than 14/1 | No deduction |
If more than one horse is withdrawn, the deductions are added together, but the total can never be more than 90p in the pound.
How a Rule 4 deduction is calculated
Say you back a horse at 3/1 with £10, and before the off a rival priced at 2/1 is withdrawn. A 2/1 horse falls in the 9/5 to 9/4 band: 30p in the pound.
- Winnings before Rule 4: £10 × 3 = £30
- Rule 4 deduction: 30% of £30 = £9
- Winnings after Rule 4: £21
- Total return: £21 + your £10 stake = £31 instead of £40
Two things to notice. The deduction comes off your winnings, never your stake. And it only matters if your horse wins — or places, on an each-way bet.
The same withdrawal with a 20/1 rival out would cost you nothing: anything bigger than 14/1 carries no deduction.
Rule 4 deductions on each-way bets
On an each-way bet, the deduction applies to the win part and the place part. Take the example above as £5 each-way in an eight-runner race (a fifth of the odds, three places), with your horse winning:
- Win part: £5 × 3 = £15, less 30% = £10.50 + £5 = £15.50
- Place part: £5 × 3/5 = £3, less 30% = £2.10 + £5 = £7.10
- Total: £23.10 instead of £28
A withdrawal can also change the place terms. If an eight-runner race becomes seven, only two places are paid. Our each-way guide has the full table.
Rule 4 with Best Odds Guaranteed
Best Odds Guaranteed doesn’t stop Rule 4. If your horse drifts and you are paid at the bigger starting price, the deduction still applies to the winnings. You can still come out ahead: our Best Odds Guaranteed guide works through an example where BOG and Rule 4 both apply.
When there’s no Rule 4 deduction
- Ante-post bets. Bets placed before the final declarations are not subject to Rule 4. The flip side is that you lose your stake if your horse doesn’t run — unless the bookmaker offers non-runner no bet.
- When a new market is formed. If a horse is withdrawn early enough for bookmakers to re-price the race, bets placed in the new market aren’t affected by that withdrawal.
- When the withdrawn horse was bigger than 14/1.
- When your own horse is the non-runner. Then your stake is returned, and in a multiple the leg counts as a winner at odds of 1.00.
Rule 4 in doubles, trebles and Lucky 15s
In a double, treble or Lucky 15, the deduction is applied to the odds of the affected selection only. If your second leg’s race lost a 2/1 shot, that leg’s 3/1 is cut to an effective 2.1/1 (3 × 0.7), and the rest of the bet carries on.
Rule 4 calculator
Enter the price you took and the deduction in our bet calculator — it applies the Rule 4 percentage to each selection, for singles, each-way bets and multiples.
Rule 4 deductions: your questions answered
What is a Rule 4 deduction?
A reduction in the winnings on a bet when a horse is withdrawn from a race after you placed your bet and there is no time to form a new market. The size depends on the withdrawn horse’s price.
How much is a Rule 4 deduction?
From 5p to 90p in the pound, based on the withdrawn horse’s odds. A 2/1 withdrawal means a 30p deduction; a 10/1 withdrawal means 5p.
Does Rule 4 come off my stake?
No. The deduction applies to your winnings only. Your stake is always returned in full on a winning bet.
Does Rule 4 apply to each-way bets?
Yes, to both the win and the place part.
Does Rule 4 apply to ante-post bets?
No. Ante-post bets aren’t subject to Rule 4, but you lose your stake if your horse doesn’t run, unless the bet is non-runner no bet.
What happens if two horses are withdrawn?
The two deductions are added together, up to a maximum of 90p in the pound.
Does Best Odds Guaranteed protect me from Rule 4?
No. BOG decides which price you are paid at; Rule 4 then applies to the winnings at that price.
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