Rule 4 Deduction Betting Explained: Why a Late Non-Runner Shrinks Settled Payouts

When a horse is scratched from a race, a winning slip struck earlier in the day returns less cash than the original odds promised. That missing return is not a penalty fee, nor is it an arbitrary deduction invented by an individual operator.

The reduction follows a published regulatory schedule designed to balance a betting market that lost one of its competitors after bets had already been accepted.

Having rule 4 deduction betting explained comes down to three operational factors: the identity of the rule-maker, the price of the withdrawn horse at the moment of notice, and the exact arithmetic used to adjust settled winnings.

The Tattersalls Scale and Who Sets the Rates

A common assumption among punters is that the bookmaker chooses how much money to hold back when a runner comes out of a race. That is incorrect. The adjustment comes directly from the Tattersalls Committee, the independent body responsible for British racing's betting rules.

In its Rules on Betting consultation document published in 2026, the Tattersalls Committee separates the authority that drafts the regulations from the bookmakers that administer them. Under these rules, bookmakers do not calculate deductions on a whim. They apply a predetermined scale based on fixed odds brackets.

The Tattersalls Committee rules specify that when a horse is withdrawn, the liability on the remaining runners "will be reduced in accordance with the following scale depending on the odds current against the withdrawn horse at the time of such official notification."

The scale is graded in pence per pound. The shorter the odds of the withdrawn horse, the heavier the deduction applied to every winning bet struck on the remaining field before that withdrawal occurred.

If an odds-on favourite comes out of a race, the chances of every other horse winning increase immediately. A horse priced at 8/1 against a dominant 1/2 favourite suddenly faces a much easier task once that favourite is back in the stable. Because the punter secured 8/1 in a market that included the favourite, the payout on that 8/1 ticket is adjusted downward to reflect the reduced competition.

According to the Tattersalls consultation document, a horse withdrawn at odds of 1/9 or shorter triggers a deduction of 90p in the pound. That 90p figure is the top tier of the official scale. As the withdrawn horse's odds lengthen, the pence-in-the-pound rate drops steadily because the departure of an outsider has a smaller effect on the remaining horses' winning chances.

How the Deduction Is Calculated from Profit

The single most frequent mistake in calculating a Rule 4 adjustment is applying the deduction to the total return rather than to the profit alone. Bookmaker guidance, including published horse racing rules from Sky Bet, confirms that the deduction applies strictly to winnings, leaving the original stake untouched.

Consider a simple £10 win bet struck at 4/1.

Under normal settlement without non-runners, the bet yields £40 in winnings plus the returned £10 stake, generating a total payout of £50.

If a rival runner is subsequently withdrawn at a price that triggers a 20p-in-the-pound deduction (a 20 per cent reduction):

1. The £10 stake is set aside and remains 100 per cent intact.
2. The gross winnings of £40 are reduced by 20p for every £1 won.
3. The deduction on £40 equals £8.00 (40 multiplied by 0.20).
4. The adjusted winnings equal £32.00 (£40 minus £8.00).
5. The final settlement pays £42.00 (£32 winnings plus the £10 stake).

If the deduction were mistakenly applied to the full £50 payout, the punter would receive £40.00, losing £2 of legitimate profit. The rule explicitly preserves the full cash stake.

The bottom end of the scale provides relief when longshots are scratched. The Tattersalls scale and bookmaker guidance, including Sky Bet's published rules, list horses priced between 10/1 and 14/1 as generating a 5p-in-the-pound deduction (5 per cent).

Where a withdrawn horse is priced at 10/1 or longer, widely reproduced bookmaker guidance states that no deduction is applied at all. When an extreme outsider is taken out, the market structure is treated as effectively unchanged for settlement purposes.

Timing, Multiple Withdrawals and Accumulator Legs

A Rule 4 deduction does not apply to every bet placed on a race. The trigger is strictly tied to timing and race entry status. Help materials from William Hill confirm that Rule 4 deductions occur only when a horse is officially withdrawn from the contest.

Punters who place their wagers after the horse has been withdrawn and after the bookmaker has formed an updated market are not subject to any Rule 4 deduction on those new bets. The price taken on a post-withdrawal wager already reflects the thinned field. The deduction applies exclusively to bets struck prior to the official notification of the withdrawal, when the old prices were still active.

When more than one horse is withdrawn from the same race before the start, multiple deductions are combined. If a 4/1 chance and an 8/1 chance are both withdrawn, the settlement system combines the individual pence-per-pound values of both non-runners into a single total deduction rate for bets placed prior to those scratches.

There is a hard ceiling on how far multiple withdrawals can shrink a payout. Under racing terms and conditions published by Sportsbet, in cases involving more than one withdrawal in a single race, the combined deduction will not exceed 0.90c in $1.00 (equivalent to 90p in the pound). Punters are guaranteed to retain at least 10 per cent of their winnings regardless of how many horses are taken out of a field.

For multi-leg bets, such as accumulators, a non-runner does not void the entire wager. Sky Bet's settlement rules state that Rule 4 reduces only the individual affected leg's payout rather than cancelling the accumulator.

The winnings on that specific leg are adjusted downward according to the Tattersalls scale, and the resulting figure rolls over into the subsequent legs of the accumulator as normal.

How Settlement Records Show the Adjustment

When checking a settled bet history online, punters can verify whether an adjusted payout stems from Rule 4.

Help guidance published by Sky Bet notes that a Rule 4 adjustment is recorded directly in the settlement view of the bet, listed as a deduction from winnings. The statement or digital slip typically identifies the deduction rate applied to the line, allowing the punter to cross-check the figure against the official scale.

One technical point remains subject to precise phrasing: while bookmaker help pages often describe the rate as depending on the horse's price at the time of withdrawal, the Tattersalls Committee consultation document uses the specific phrase "odds current against the withdrawn horse at the time of such official notification." In practice, if a horse drifts or shortens immediately before the official notice is posted, the official declaration time sets the benchmark.

To verify a reduced payout, a punter needs three pieces of data from the race card: the time the bet was placed, the time the non-runner was officially withdrawn, and the official price of the withdrawn horse at the moment notification was logged. If the bet was placed before that notification time, the adjustment on the account statement should match the published Tattersalls pence-per-pound tier exactly.

Playing safely

Everything above assumes you are 18 or over and betting money you can afford to lose. Every operator licensed in Great Britain must give you deposit limits, a reality check, a time-out and self-exclusion from inside your account, and must connect to GAMSTOP, the free national scheme that blocks you from every licensed British site at once. If betting has stopped being entertainment, the National Gambling Helpline is free on 0808 8020 133, open around the clock, and our own page on gambling harm lists the rest.

Written and checked by the GBbet editorial desk

Licence numbers are checked against the Gambling Commission public register; bonus terms, minimum odds and payment limits are read from the operator’s own published pages. Nothing here is a personal opinion, and no page is rated by stars — how we work · about the desk.

Last checked 27 September 2026.