Horse Racing Rule 4: Why a Winning Bet Pays Less

Rule 4 is a horse-racing deduction from winnings when a runner is withdrawn and the applicable rules require an adjustment to bets on the remaining horses. The rate follows the withdrawn horse's price, not the winner's. For an ordinary winning single, it reduces the profit portion; the original stake is added back. Betfair's Rule 4 explanation separates those amounts in its worked calculation.

The calculations below concern cash-staked, win-only fixed-odds singles after final declarations, using British and Irish racing conventions and named operators' published rules checked on 2 October 2026. They explain a settlement, not how to choose a horse. Exchange bets, ante-post markets and other bet types need their own terms.

The Rule 4 deduction follows the horse that leaves

A withdrawal removes one possible winner from the field. Bookmakers can revise the prices offered for subsequent bets. Rule 4 addresses the earlier tickets whose prices were accepted while that horse was still included.

The price matters because withdrawing a heavily favoured runner changes the remaining field more than removing a long-priced outsider. This does not make a six-horse race six equal chances of winning. The table uses prices as its reference; it does not assign each runner an equal probability.

The scale below is Rule 4(c) in the Tattersalls rules published by Sandown Park. That document is dated January 2015, not a new 2026 rulebook. Its third column here is our arithmetic: the amount left from each £1 of profit after the stated deduction. Fractional ranges are written from shorter to longer prices.

The scale lists traditional quoted prices. Betfair specifies the last available Betfair price at withdrawal and says an unlisted price uses the next higher quoted price: its example places 21/5 in the 9/2 bracket. The Sportsbook horse-racing rules also distinguish withdrawals from a horse coming under starter's orders but refusing to race. A horse failing to finish is not automatically a non-runner.

£120 becomes £100, without taking £4 from the stake

Consider a hypothetical £20 win-only bet accepted at 5/1. The selected horse wins outright. Before any adjustment, the ticket would return £100 profit plus the £20 stake, or £120 total.

Suppose another runner, priced at 4/1 at the relevant withdrawal time, was removed after acceptance and a 20p Rule 4 applies. That means a deduction of 20% from the £100 profit. The result is £80 profit plus £20 returned stake: £100 total.

The calculation for this single is: total return = stake + (original profit × (1 − deduction rate)). With decimal odds, original profit is stake × (decimal odds − 1). Decimal 6.00 therefore produces the same £100 original profit as fractional 5/1 on a £20 stake.

Applying 20% to the entire £120 would produce £96. That would incorrectly remove £4 from the returned stake as well. Sky Bet's Rule 4 guidance says the stake is returned in full, while identifying dead heats as a separate qualification. Our guide to voids, pushes and dead heats explains why a shared finishing position needs another calculation.

The £100 here is a hypothetical total return, not evidence that an actual account was settled correctly. Bonus stakes, place bets and accumulators are outside this example.

The time on the ticket changes which market applies

An earlier ticket and one accepted after the bookmaker reforms its market can face different deductions. The first was priced with the withdrawn runner included. The second was priced against the revised field. A later withdrawal can then affect that second market too.

Sky Bet's guidance illustrates successive withdrawals with separate treatment for bets accepted before and after its first market revision. It caps combined deductions at 90p per £1 of winnings. Reconstructing such a settlement requires the sequence of withdrawals and the relevant market prices, not simply the last number displayed beside each horse.

Starting price, or SP, is the price used at the race's start rather than an earlier price taken by the customer. Betfair says SP bets can also face a deduction when a late withdrawal leaves insufficient time to form a new market. Its Future Racing and non-runner provisions accept ante-post bets on an all-in basis with specified exceptions: a non-participating selection is generally a loser. The refund assumed for a normal non-runner ticket cannot be carried across to that market.

Operator concessions also matter. William Hill's Rule 4 terms waive a total market deduction of 5p in the pound. Its published explanation places ordinary Rule 4 withdrawals after final declarations and before starter's orders. A generic deduction table cannot show whether an operator has waived a particular charge.

An accepted fixed-odds price is still meaningful. Our article on odds changing after a bet is accepted separates ordinary market movement from specific settlement clauses. Rule 4 supplies a named calculation for a withdrawal; a new, shorter offer on the screen alone does not.

Betfair Exchange uses a different base

Betfair Sportsbook and Betfair Exchange share a brand, but their non-runner calculations are different. Under the Exchange horse-racing rules, a qualifying reduction factor in a win market reduces the matched decimal price. It does not use the sportsbook table to deduct a percentage from profit.

For example, assume a pre-race Exchange back bet was matched at decimal 6.00 and a 20% reduction factor applies. The revised price is 6.00 × 0.80 = 4.80. A winning £20 back bet then has a £96 gross return before any commission. By contrast, the sportsbook example above keeps the stake outside the profit deduction and returns £100.

Using the same percentage in both examples isolates the different bases. It does not imply that a runner priced at 4/1 receives a 20% Exchange reduction factor. Betfair assigns that factor separately. Its win-market threshold is 2.5%; place-market reductions operate on potential winnings instead. The win-market formula here must not be reused for a place bet.

Product labels also matter when a customer closes a position early. Cash out on a sportsbook and an exchange can involve different transactions. These examples assume the original bet remains open for ordinary race settlement; they do not recalculate an accepted cash-out settlement.

A smaller return still needs an explanation

Great Britain's Gambling Commission recognises Rule 4 among practices that may fairly amend potential returns on open bets. Its guidance on reducing winnings still rejects unfair terms and broad payout reductions linked to commercial success. Naming Rule 4 does not answer every question about a disputed settlement.

For the win-only single in this article, a reproducible explanation needs the accepted stake and odds, the withdrawal time, the withdrawn runner's applicable price, the deduction rate and the profit calculation. The account record should also establish whether the bet preceded the reformed market. Each-way terms, multiple withdrawals or a dead heat require the additional rules for those circumstances.

A settlement labelled "20p Rule 4" should identify which withdrawn runner supplied that rate and show where the deduction entered the arithmetic. On the hypothetical £20 ticket above, the explanation must reconcile £80 profit with a £100 total return.