Rule 4 Deductions Explained: Table, Examples and Dead Heats

You backed a horse at 6/1, it won, and the return is smaller than the 6/1 you were promised. On the bet slip there is a line that reads "R4 20p" or "Rule 4 deduction applied". That line is the most common reason a winning racing bet in Britain or Ireland pays less than expected, and it follows a fixed scale that you can check yourself.

This page is the full reference: why Rule 4 deductions exist, the complete deduction table, how the deduction is worked out on singles, each-way bets and multiples, how it treats starting price bets and ante-post bets, and how dead heat rules split a stake when horses cannot be separated. Every example shows the arithmetic in pounds. For the wider picture of racing bets, start with the horse racing betting guide.

Why Rule 4 deductions exist

Rule 4 takes its name from Rule 4(c) of the Tattersalls rules on betting, the long-standing code that UK and Irish bookmakers either apply directly or copy into their own racing rules. It deals with one situation: a horse is withdrawn from a race after the betting market has formed and before it comes under starter's orders.

When that happens, every horse left in the race has a better chance than it had a minute earlier. If a 2/1 favourite in a six-runner race comes out, the remaining five share the chance the favourite used to carry. Anyone who took a fixed price before the withdrawal now holds odds that are too big for the new race. The bookmaker reprices the market for new bets, and Rule 4 adjusts the bets already struck by taking a set amount from the winnings.

The size of the deduction tracks the withdrawn horse's chance. A 7/2 shot has an implied probability of about 22% (1 divided by the decimal price of 4.50), and the table deducts 20p in the pound for it. A 20/1 outsider barely changes anyone else's chances, so it triggers nothing.

The Rule 4 deduction table

The deduction depends on the withdrawn horse's price at the time it was withdrawn, not on the price you took and not on its morning price. This is the scale most British bookmakers publish in their racing rules, with decimal equivalents in brackets:

• 1/9 or shorter (1.11 or shorter): 90p in the pound
• 2/11 to 2/17 (1.18 to 1.12): 85p
• 1/4 to 1/5 (1.25 to 1.20): 80p
• 3/10 to 2/7 (1.30 to 1.29): 75p
• 2/5 to 1/3 (1.40 to 1.33): 70p
• 8/15 to 4/9 (1.53 to 1.44): 65p
• 8/13 to 4/7 (1.62 to 1.57): 60p
• 4/5 to 4/6 (1.80 to 1.67): 55p
• 20/21 to 5/6 (1.95 to 1.83): 50p
• Evens to 6/5 (2.00 to 2.20): 45p
• 5/4 to 6/4 (2.25 to 2.50): 40p
• 8/5 to 7/4 (2.60 to 2.75): 35p
• 9/5 to 9/4 (2.80 to 3.25): 30p
• 12/5 to 3/1 (3.40 to 4.00): 25p
• 16/5 to 4/1 (4.20 to 5.00): 20p
• 9/2 to 11/2 (5.50 to 6.50): 15p
• 6/1 to 9/1 (7.00 to 10.00): 10p
• 10/1 to 14/1 (11.00 to 15.00): 5p
• Over 14/1 (over 15.00): no deduction

"Pence in the pound" is a percentage of your winnings. A 25p deduction removes 25% of the profit on the bet. Some bookmakers waive a deduction of only 5p in the pound, while others apply it, so the bottom band is the one most likely to differ between operators.

Rule 4 deductions on a single: worked example

Rule 4 comes off your winnings, never your stake. Say you have £10 on a horse at 6/1 in the morning. Later, a rival priced at 7/2 is withdrawn, which puts it in the 20p band. Your horse wins.

• Winnings before the deduction: £10 × 6 = £60
• Deduction: 20% of £60 = £12
• Winnings after the deduction: £48
• Total return with the £10 stake: £58 instead of £70

In effect, 6/1 has become 4.8/1. Had the withdrawn horse been 3/1, it would sit in the 25p band: £60 less 25% is £45, and the return would be £55. The band edges matter, which is why the withdrawal price on the settled bet is worth checking against the table.

When more than one horse is withdrawn

Deductions for several withdrawn horses are added together. If a 2/1 shot (30p) and a 5/1 shot (15p) both come out, the combined deduction is 45p. On £10 at 4/1, winnings of £40 lose 45% (£18), leaving £22, and the return is £32.

There is a ceiling. Under the British bookmaker scale the total cannot exceed 90p in the pound, however many horses are withdrawn. Take an extreme case: a 1/2 favourite (65p) and a 2/1 second favourite (30p) are both withdrawn, a nominal 95p. With £10 on a 10/1 shot that goes on to win, a 90p cap leaves £10 of the £100 winnings and a return of £20. Under a 75p cap, the same bet keeps £25 of winnings and returns £35. Reaching the cap is rare.

If horses come out at different times, bookmakers usually form a new market after the first withdrawal. Bets struck in the new market are only affected by later withdrawals, and the deduction uses the prices in the market where your bet was placed.

Rule 4 on SP, early prices and board prices

Rule 4 is mainly a fixed-odds rule. It applies to early prices and board (show) prices taken before the withdrawal was announced, because those prices assumed the withdrawn horse would run.

Starting price bets are normally not affected. The starting price (SP) is the official price at the off, and when a horse is withdrawn in good time, SP is returned on the race as it actually runs, so the smaller field is already in the price. The exception is a horse withdrawn at the start, for example one that refuses to enter the stalls or gets loose, when there is no time to form a new market. In that case SP bets can be subject to a deduction as well, set by the withdrawn horse's price at the moment it came out.

Many bookmakers offer best odds guaranteed on UK and Irish races, paying the bigger of your taken price and SP. How that concession interacts with a Rule 4 deduction is set out in each operator's terms, so read them before assuming the bigger price is paid in full.

Rule 4 in each-way bets and multiples

An each-way bet is a win bet and a place bet, and Rule 4 applies to both parts at the same rate. Suppose you have £5 each-way at 8/1 with place terms of 1/5 the odds for three places, a total stake of £10. A 2/1 runner is withdrawn, a 30p deduction.

If your horse wins, the win part makes £40 before the deduction and £28 after, returning £33. The place part pays at 8/5: £8 of winnings becomes £5.60, returning £10.60. The total is £43.60, against £58 without the withdrawal. If the horse only places, the return is £10.60 on a £10 stake.

Withdrawals can also change the place terms themselves. Most bookmakers pay places on the number of runners that actually start, so an eight-runner race that loses a horse can drop from three places to two. Each-way bets explained covers place terms in full, and the each-way calculator works out returns for any price and fraction.

In a multiple, the deduction applies only to the leg run in the affected race. Take a £10 double: leg one at 6/1 carries a 20p deduction, leg two wins at 2/1. Leg one's odds are reduced to 4.8/1, which is 5.80 in decimal, so the double returns £10 × 5.80 × 3.00 = £174 instead of £210. Full-cover bets such as a Yankee or a Lucky 15 apply the reduced price to every line that includes that leg; see full-cover bets explained for how the lines are built.

Ante-post bets and non-runner no bet

Ante-post bets are struck before the final declarations, often days or weeks before the race. Rule 4 does not apply to them. The trade-off is the risk on your own horse: if it does not run, the bet is lost, not void.

Non-runner no bet (NRNB) is a concession that removes most of that risk. On markets marked NRNB, your stake is returned if your horse does not run. Bookmakers usually switch big races to NRNB some days before the event, and on festival races or the Grand National sometimes earlier, but only bets placed after the concession starts are covered. Whether a Rule 4 deduction can apply to an NRNB bet when rival horses come out is set by the bookmaker's own terms, so check them for the race you are betting on. The Grand National betting guide shows how this plays out in a forty-runner field.

Bets placed on the day, after declarations, follow the normal rules: if your horse is withdrawn, a single is void and the stake comes back, and in a multiple the leg is treated as a non-runner while the rest of the bet stands.

Dead heat rules in horse racing

A dead heat is declared when the judge, using the photo finish, cannot separate two or more horses for a position. Under the dead heat rule, your stake is divided by the number of horses sharing the position. That part of the stake is paid at full odds, and the rest is lost.

Two-way dead heat for first: £10 at 6/1. Half the stake, £5, is settled at 6/1 and returns £35. The other £5 loses. Profit £25 instead of £60.

Three-way dead heat for first: £10 at 9/1. A third of the stake, £3.33, is settled at 9/1 (10.00 in decimal) and returns £33.33. A small profit on a £10 bet.

Dead heat with a Rule 4 deduction: both rules apply. £10 at 6/1 with a 20p deduction, dead-heating for first with one other horse, settles £5 at the reduced price of 4.8/1 and returns £5 × 5.80 = £29.

Dead heat for a place in each-way bets

The dead heat rule only bites when the tie crosses the last paying place. If two horses dead-heat for second in a race paying three places, both still finish inside the places and both place parts are paid in full.

The reduction applies when horses tie for the final place. Take £5 each-way at 12/1, 1/4 the odds, three places. Your horse dead-heats for third with one other runner. The win part loses. The place part is settled on half the place stake, £2.50 at 3/1, which returns £10. You get your £10 total stake back and nothing more, where a clean third would have returned £20.

Golf uses the same rule, and ties are far more common there, so top-five and top-ten bets often pay a fraction of the expected amount. The golf betting guide has examples.

Before you place the bet

A quick routine before you confirm the slip:

• Check whether your slip shows a fixed price or SP. Rule 4 mainly affects fixed prices.
• Look at the runners list for doubtful starters, such as horses with ground concerns, before taking an early price.
• If you bet ante-post, confirm whether the market was NRNB when you placed the bet.
• After a withdrawal, find the withdrawn horse's price and check the band in the table.
• On each-way bets, recheck the place terms once the final field size is known.
• Keep stakes within a budget you set before racing starts, and do not raise them to recover a deduction or a losing day.

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