Definition
Rule 4 Deduction
Also known as Rule 4, R4, Tattersalls Rule 4
By Abhinav VasudevanReviewed Editorial policy
In short
A Rule 4 deduction reduces winnings on a horse race when another runner is withdrawn after betting has opened. The size of the deduction depends on the withdrawn horse's price. The shorter it was, the bigger the cut.
Rule 4 exists because a withdrawal changes the race. If you backed a horse at 10/1 in a field of twelve and the odds-on favourite is then withdrawn, your horse’s real chance has improved considerably, but you are still holding a 10/1 price. Rule 4 claws back the difference.
It comes from the Tattersalls Committee rules that govern British horse racing betting.
The deduction scale
Based on the withdrawn horse’s price at the time of withdrawal:
| Withdrawn horse’s odds | Deduction from winnings |
|---|---|
| 1/9 or shorter | 90p in the £ |
| 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 |
| 100/30 to 4/1 | 20p |
| 9/2 to 11/2 | 15p |
| 6/1 to 9/1 | 10p |
| 10/1 to 14/1 | 5p |
| Longer than 14/1 | No deduction |
Applying it
The deduction applies to winnings, not the total return, and your stake is never touched.
A £10 bet at 10/1 wins £100. If a 2/1 shot was withdrawn, the deduction is 25p in the pound:
- £100 × 0.25 = £25 deducted
- Winnings become £75, plus your £10 stake = £85 returned
When it does not apply
- Starting price bets are exempt, because the SP already reflects the reduced field.
- Ante-post bets are exempt. One of the genuine advantages of betting early.
- Withdrawals before the market reopens may not trigger it, depending on timing.
- Multiple withdrawals produce combined deductions, capped at 90p in the pound.
Rule 4 applies to both halves of an each-way bet.
Common questions
How much is a Rule 4 deduction?
It depends on the withdrawn horse's price. A 2/1 withdrawal costs 25p in the pound of your winnings, evens costs 45p, and anything longer than 14/1 costs nothing. Deductions apply to winnings only, never to your stake.
When does Rule 4 not apply?
On starting price bets, because the SP already reflects the smaller field, and on ante-post bets. It does apply to both halves of an each-way bet, and multiple withdrawals combine up to a cap of 90p in the pound.