What is Rule 4?
Rule 4 is a horse racing adjustment applied when a horse is withdrawn after final declarations. It reduces the potential profit on existing bets to reflect the smaller field and the increased chances of the remaining runners.
The deduction applies to winnings only, not the original stake. It is calculated based on the withdrawn horse’s odds: horses with shorter odds cause larger reductions, while long-shot withdrawals have minimal impact. Rule 4 ensures payouts remain fair when a race is affected by withdrawals.
Related article: What is an Insurance Bet in horse racing?
Why Rule 4 exists and when it applies
Odds in horse racing are calculated based on the full field of declared runners. When a horse is withdrawn, the remaining horses have a higher statistical chance of winning. Rule 4 adjusts existing bets to reflect this change without voiding them.
A Rule 4 deduction is typically applied when:
- A horse is withdrawn after the final declarations
- The withdrawal occurs before the race starts
- The bet was placed at fixed odds before the withdrawal
Rule 4 usually applies to win and place markets in UK horse racing. Ante-post bets are generally excluded, as non-runners in those markets are not refundable.
How does Rule 4 work?
The deduction is calculated based on the odds of the withdrawn horse at the time it was pulled from the race. Shorter odds (indicating favourites) lead to larger deductions, while longer odds result in smaller adjustments.
Rule 4 is commonly described as "pence in the pound." For example, a 10p Rule 4 means 10% of your profit is deducted.
Example
Imagine you bet £10 on a horse at 5/1 odds (American odds: +500).
- Original Potential Profit: £50 (plus your £10 stake back = £60 total).
- Event: A rival horse (the favourite) is withdrawn at odds of 2/1.
- Rule 4 deduction: Looking at the table, a 2/1 withdrawal triggers a 30p in the £1 (30%) deduction.
- Calculation: 30% of your £50 profit is £15.
- Adjusted profit: £35 (£50 - £15).
- Final Payout: You receive £45 (£35 profit + £10 stake) instead of the original £60.
Standard Rule 4 deduction table
Odds of Withdrawn Horse | Deduction (per £1 won) | Percentage of Profit |
|---|---|---|
1/9 or shorter | 90p | 90% |
2/11 to 2/17 | 85p | 85% |
1/4 to 1/5 | 80p | 80% |
3/10 to 2/7 | 75p | 75% |
2/5 to 1/3 | 70p | 70% |
8/15 to 4/9 | 65p | 65% |
8/13 to 4/7 | 60p | 60% |
4/5 to 4/6 | 55p | 55% |
20/21 to 5/6 | 50p | 50% |
Evens to 6/5 | 45p | 45% |
2/1 to 9/4 | 30p | 30% |
5/1 to 9/1 | 10p | 10% |
10/1 to 14/1 | 5p | 5% |
Over 14/1 | No Deduction | 0% |
Types of Rule 4
Standard Rule 4(c)
Tattersalls Rule 4(c) is the industry benchmark for horse racing. It applies to fixed-odds bets when a horse is withdrawn post-declaration. Winnings are reduced by a specific "pence in the pound," determined by the withdrawn horse’s price at its exit.
Cumulative Rule 4 (multiple non-runners)
If multiple horses are withdrawn due to track conditions, individual deductions are stacked together. For instance, two 10p deductions result in a 20p total. To protect bettors, these charges are capped at 90%, ensuring you always receive your original stake.
Reformed market Rule 4
Bookmakers often suspend betting to update odds for the remaining horses after a withdrawal. Bets placed before this reform are subject to Rule 4, whereas those placed after the re-opening are exempt, as they already reflect the new race probability.
Reserve runner exception
In specific races, if a reserve horse is permitted to fill a vacant stall, the Rule 4 deduction is often waived. Since the field size remains unchanged, the statistical win probability for your horse stays the same, allowing your original payout.
Each-way Rule 4
This affects both the "Win" and "Place" profit of a horse wager. Field reductions may also shorten place terms (e.g., 8+ runners drop to top 3 at 1/5 odds). If a withdrawal significantly shrinks the field, the bookmaker may adjust the each-way terms, potentially reducing the number of paid places from three down to just two.
Conclusion
Rule 4 is designed to maintain fairness when a horse is withdrawn or a race field is reduced. It adjusts winnings based on the withdrawn horse’s odds, ensuring that payouts accurately reflect the updated race conditions. Understanding how Rule 4 works helps bettors interpret deductions and the resulting payouts.
Frequently asked questions (FAQs)
What triggers a Rule 4 deduction?
A Rule 4 deduction is triggered when a horse is withdrawn from a race after the final declarations but before the event starts. This can happen due to various reasons, such as injury, illness, or other circumstances that prevent the horse from participating.
Does Rule 4 affect my original stake?
No, Rule 4 only affects the winnings from your bet, not your original stake. If a deduction is applied, it will only reduce the profit you would have made from your bet, not the initial amount you wagered.
How is the Rule 4 deduction calculated?
The deduction is based on the odds of the withdrawn horse at the time it is pulled from the race. The closer the withdrawn horse was to being a favourite (i.e., the shorter its odds), the higher the deduction. This helps reflect the increased chances of the remaining competitors, ensuring the odds are adjusted fairly.
Can multiple Rule 4 deductions apply in one race?
Yes, if more than one horse is withdrawn from the race, each withdrawal triggers its own deduction. These individual deductions are combined, but there is a cap on the total amount, typically up to 90% of your potential profit.
Do ante‑post bets get Rule 4 deductions?
No, ante-post bets (pre-declarations) are usually exempt from Rule 4 deductions because non-runners are non-refundable; you lose the stake without adjustment or voiding. This contrasts with post-declaration bets, where Rule 4 applies to reflect the reduced field.