Rule 4 Deductions Explained
Rule 4 is the mechanism bookmakers use to adjust payouts when a horse is withdrawn from a race after the market has formed. When a runner is removed, the remaining horses all become more likely to win — but the odds on your bet were set when the full field was intact. Rule 4 corrects for this by applying a deduction to your winnings. The deduction is not arbitrary. It is calculated from the price of the withdrawn horse at the time of withdrawal.
How the Deduction Is Calculated
The deduction is a percentage taken from your winnings — not from your stake. It is applied after the race, to the profit element of your return. The percentage is determined by the price of the non-runner at the time it was withdrawn.
| Price of Non-Runner | Deduction |
|---|---|
| 1/9 or shorter | 90p in the £ |
| 2/11 to 2/17 | 85p in the £ |
| 1/4 to 1/5 | 80p in the £ |
| 3/10 to 2/7 | 75p in the £ |
| 2/5 to 1/3 | 70p in the £ |
| 8/15 to 4/9 | 65p in the £ |
| 8/13 to 4/7 | 60p in the £ |
| 4/5 to 4/6 | 55p in the £ |
| 20/21 to 5/6 | 50p in the £ |
| Evens to 6/5 | 45p in the £ |
| 5/4 to 6/4 | 40p in the £ |
| 8/5 to 7/4 | 35p in the £ |
| 9/5 to 9/4 | 30p in the £ |
| 12/5 to 3/1 | 25p in the £ |
| 16/5 to 4/1 | 20p in the £ |
| 9/2 to 11/2 | 15p in the £ |
| 6/1 to 9/1 | 10p in the £ |
| 10/1 to 14/1 | 5p in the £ |
| Over 14/1 | No deduction |
When Rule 4 Applies
Rule 4 applies whenever a horse is withdrawn after the final declaration stage and the bookmaker has already priced the market. The most common scenarios are late veterinary withdrawals, going-related withdrawals on the morning of the race, and horses that refuse to enter the stalls at the start.
Rule 4 does not apply to ante-post bets. If you backed a horse ante-post and a different runner is later withdrawn, your bet stands at the original price with no deduction. This is one of the advantages of ante-post betting — you are insulated from Rule 4 adjustments. For more on this, see Ante-Post Betting Explained.
Multiple Withdrawals
If more than one horse is withdrawn, the deductions are cumulative. The individual deductions are simply added together. If two horses are withdrawn with deductions of 25p and 15p respectively, the combined deduction is 40p in the £. The Tattersalls rules cap the total at 90p in the £ — so no matter how many short-priced runners are withdrawn from the same race, you will always keep at least 10p of every winning pound.
In extreme cases — such as a Cheltenham race where the first two in the market are withdrawn on the morning — the combined deduction can comfortably exceed 50p and occasionally reach the 90p ceiling. That effectively wipes out the bulk of your winnings even on a successful bet. If you see multiple late withdrawals in a race, recalculate your expected return before deciding whether the bet still holds value — the Bet Calculator handles Rule 4 deductions on singles, each-way bets and multiples, including cumulative deductions across more than one non-runner.
For the full picture on what happens when horses are withdrawn, see Non-Runner Rules Explained. For how deductions interact with each-way bets, see Each-Way Betting Explained.
Try the Calculator
Calculate Rule 4 deductions on your winning bet — enter odds, stake, and the withdrawn runner’s price to see exactly how much is taken off your return.
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