A Rule 4 deduction is taken from your winnings when a horse is withdrawn from a race after the betting market has formed and there is no time to form a new market. It is quoted in pence per pound, it comes off winnings only and never off your stake, and its size depends on the price of the withdrawn horse.
What is a Rule 4?
Rule 4 comes from the Tattersalls rules and exists because a withdrawal changes the race. When a runner drops out, especially a fancied one, every remaining horse has a better chance than the market suggested when the prices were set. If there is no time to form a new market, the prices already taken no longer reflect the race that is actually run, so a proportion of the winnings on successful bets is deducted to rebalance them.
The deduction is applied to winnings, not stakes, and it is always expressed in pence for every pound of winnings. If your horse wins, the stake comes back in full and only the profit is reduced. A losing bet is unaffected, because there are no winnings to deduct from.
How much is the deduction?
The scale is set by the price of the withdrawn horse: the shorter its price, the more its absence changes the race and the bigger the deduction. A horse priced bigger than 14/1 is judged to make too little difference, so no deduction is made. Points on the scale include:
- 1/9 or shorter: 90p in the pound
- evens: 45p in the pound
- 2/1: 30p in the pound
- 10/1 to 14/1: 5p in the pound
- bigger than 14/1: no deduction
If several horses are withdrawn from the same race, the deductions are added together. However, the total can never exceed 90p in the pound, no matter how many runners come out, so a winning bet always keeps at least a tenth of its profit as well as the full stake.
How to calculate a Rule 4 return
Suppose you stake £10 on a horse at 4/1 and it wins. Without any withdrawal, that bet makes £40 profit and returns £50 including the stake. Now suppose a rival priced at 2/1 was withdrawn after the market formed, bringing a deduction of 30p in the pound.
The deduction applies to the £40 profit only: £40 multiplied by 0.30 is £12. The profit falls to £28, and with the £10 stake returned in full the total return is £38.
The same method works for any deduction. Convert the pence per pound into a share of the winnings, take it off the profit, then add the stake back. Working through the figure yourself is the simplest way to understand a settled return that looks smaller than expected, and it shows why the stake itself is never touched.
Rule 4 does not change whether a bet wins or loses; it only adjusts the payout when the field changes late. Gambling is for adults 18 and over and costs money; UK players can set deposit limits, use GAMSTOP or call the National Gambling Helpline on 0808 8020 133.
