Rule 4 Deductions: Why Your Winning Bet Pays Less Than It Should
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The Moment Your Winning Bet Shrinks
I backed a horse at 6/1 in a novice hurdle at Cheltenham, watched it cruise home, and then checked my return to find I had been paid at something closer to 4/1. The explanation was two words on the slip: Rule 4. A horse had been withdrawn after I placed my bet but before the race started, and a chunk of my winnings had been deducted to account for the changed market. It felt wrong. It was, in fact, perfectly logical – but that did not stop it from stinging.
Rule 4, properly known as Tattersalls Rule 4(c), is a deduction applied to fixed-odds bets when a horse is withdrawn from a race after the market has formed. It exists to rebalance the odds in a market that has been distorted by a non-runner. Without it, every other runner’s price would be artificially generous – priced against a field that no longer exists.
What Rule 4 Is
When you place a fixed-odds bet on a horse race, the price reflects the entire field at that moment. If a runner is subsequently withdrawn, the remaining horses have a better chance of winning than their original odds imply. Rule 4 corrects for this by deducting a percentage from your winnings based on the price of the withdrawn horse.
The logic is sound even if the execution feels harsh. If the 2/1 favourite is withdrawn, the remaining runners are collectively more likely to win. Your 6/1 shot is no longer competing against the strongest horse in the race. The price you took – 6/1 – was set when that favourite was in the field. Rule 4 adjusts your payout to approximate what the odds would have been had the favourite never been in the market.
Rule 4 applies only to bets placed before the withdrawal. If you bet after the horse has been removed and the market has been repriced, no deduction applies. UK horse racing generates £766.7 million in gross gambling yield from remote betting, and the integrity of pricing across millions of bets depends on Rule 4 functioning as designed.
The Deduction Table
The size of the deduction depends on the price of the withdrawn horse at the time of withdrawal. The shorter the price, the bigger the deduction – because a short-priced withdrawal has a larger impact on the remaining market.
The scale runs from 90p in the pound for a withdrawn horse priced at 1/9 or shorter, down to 5p for a horse priced between 14/1 and 16/1, and no deduction at all for withdrawals at longer than 16/1. In between: a 2/1 withdrawal triggers a 30p deduction; a 4/1 withdrawal triggers 20p; a 7/1 withdrawal triggers 10p; a 10/1 withdrawal triggers 10p. The exact table is published by Tattersalls and applied uniformly by all licensed bookmakers.
The deduction is applied to your winnings, not your stake. If you backed a horse at 6/1 with a £10 stake and a Rule 4 deduction of 20p in the pound applies, your winnings before deduction are £60. The deduction removes 20% of that: £12. Your net winnings are £48, plus your £10 stake back, for a total return of £58 instead of £70. That £12 difference is the cost of the market distortion caused by the withdrawal.
I have committed the common deduction levels to memory – 30p for an evens or shorter withdrawal, 20p for around 3/1, 10p for around 7/1 – because knowing them on the spot saves the frustration of discovering the deduction only when you check your account.
Worked Examples
Take a practical scenario. You back Horse A at 5/1 for £10. Before the race, Horse B – priced at 3/1 – is withdrawn. The Rule 4 deduction for a 3/1 withdrawal is 25p in the pound. Horse A wins.
Your gross winnings: £50 (5 x £10). Rule 4 deduction: 25% of £50 = £12.50. Net winnings: £37.50. Total return: £47.50 (winnings plus stake). Without Rule 4, you would have received £60. The deduction cost you £12.50.
Now consider the same bet but with a longer-priced withdrawal. Horse B was 12/1 instead of 3/1. The deduction drops to 5p in the pound. Your gross winnings: £50. Deduction: 5% of £50 = £2.50. Net winnings: £47.50. Total return: £57.50. The impact is much smaller because the withdrawn horse had less influence on the market.
The key point: Rule 4 hurts most when the withdrawal is a short-priced horse. A favourite going lame in the paddock can strip 30% or more from every winning bet placed before the withdrawal. On a £100 win at 4/1, a 30p deduction costs £120 – enough to turn a satisfying result into a disappointing one.
Multiple Withdrawals
Occasionally, more than one horse is withdrawn from a race after the market has formed. When this happens, the deductions are combined – but not simply added together. The combined deduction follows a specific formula that accounts for both withdrawals.
If Horse B at 3/1 (25p deduction) and Horse C at 7/1 (10p deduction) are both withdrawn, the combined deduction is not 35p. Instead, it is calculated as: 1 – (1 – 0.25) x (1 – 0.10) = 1 – 0.675 = 0.325, or 32.5p in the pound. The combined deduction is slightly less than the sum of the individual ones because each withdrawal adjusts the market independently.
In extreme cases – a race where three or four runners are withdrawn – the total deduction can approach the maximum of 90p in the pound, leaving punters with a fraction of their expected winnings. Betting turnover on British racing fell 4.3% in 2025 versus 2024, and races with thin fields and multiple withdrawals are an increasing concern across core fixtures where field sizes have been declining.
If the combined deductions reach 75p or more, many bookmakers will offer the option to void bets entirely. This is not a universal rule but a common practice – check the specific terms of your bookmaker before assuming you can walk away from a heavily deducted race.
Avoiding Rule 4 Hits
You cannot eliminate Rule 4 risk entirely, but you can manage it. Three practical approaches have served me well.
First, bet late. The closer to the off you place your bet, the less likely a withdrawal will occur between your bet and the race. Bets placed in the final minutes before the off carry minimal Rule 4 exposure. The trade-off is that late betting means you may miss a longer early price – a tension that every punter navigates differently.
Second, take SP. Starting price bets are not subject to Rule 4 because SP already reflects the post-withdrawal market. If you take SP and a horse is withdrawn, the SP of every remaining runner is recalculated to account for the non-runner. You receive the adjusted price, no deduction necessary. This is one of the genuine advantages of SP over a fixed early price, and it is worth understanding how the starting price mechanism works to use it deliberately.
Third, use Best Odds Guaranteed where available. BOG gives you the better of your board price and SP. If a withdrawal triggers Rule 4 on your board price but the SP is higher than the deducted board price, BOG pays you at SP without the deduction. This does not always save you – sometimes the deducted board price is still higher than SP – but it provides a partial hedge against the worst Rule 4 outcomes.
Rule 4 is not a penalty; it is a market correction. The deduction ensures that fixed-odds bets remain fair when the field changes. Accepting it as a feature of the system, rather than resenting it as a personal loss, is part of betting with clear eyes.
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Published by the Furlongcraft team.