What is Rule 4 in betting?
Rule 4 — A deduction from winning bets when a horse is withdrawn late and the market can’t be reformed.
Also: Rule 4(c) deduction
Rule 4 is a fair-play deduction. If a horse is withdrawn shortly before the off — too late to form a new market — everyone left in the race becomes more likely to win, so their odds were, in hindsight, too big. Rule 4 corrects for that by taking a set amount out of winning bets.
The size of the deduction depends on the withdrawn horse’s price: the shorter it was (the more likely it was to win), the bigger the deduction. It’s taken per £1 of winnings. As a rough guide:
| Withdrawn horse’s odds | Deduction per £1 |
|---|---|
| 1/9 or shorter | 90p |
| Around evens | 50p |
| 2/1 | 33p |
| 4/1 | 20p |
| 10/1 | 9p |
| Bigger than 14/1 | none |
So back a winner to make £5 profit while a 2/1 shot is withdrawn, and about 33p in the £ comes off — roughly £1.65, leaving ~£3.35. It only applies to late withdrawals; if there’s time to reform the market, there’s no deduction.
Related terms
Frequently asked questions
Why did I get a Rule 4 deduction?
Because a horse was withdrawn too late to reprice the race. The remaining runners’ odds were effectively too generous, so a deduction restores fairness.
Does Rule 4 apply to every non-runner?
No — only late withdrawals where the market can’t be reformed. Earlier non-runners are simply removed with no deduction.
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