Rule 4 Deductions Explained: Why Your Winnings Just Got Smaller
You backed a winner at 8/1, the bookmaker paid you out at closer to 7/1, and the settlement slip mentions something called "Rule 4". Nothing has gone wrong. A horse was withdrawn after you placed your bet, and the price of every remaining runner got adjusted to account for it.
This page explains exactly how that adjustment works, gives you the full deduction table, and shows you how to work out what you'll actually be paid.
TL;DR: When a horse is withdrawn after betting has opened, bookmakers deduct a fixed amount from the winnings (not the stake) of bets already placed. The size of the deduction depends on the withdrawn horse's price: the shorter the non-runner, the bigger the deduction, from 5p per £1 for a 14/1 shot up to 90p per £1 for a long odds-on favourite. Horses over 14/1 trigger no deduction at all.
What is Rule 4?
Rule 4 is shorthand for Tattersalls Committee Rule 4(c), the industry-standard rule for settling bets when a horse is withdrawn after a market has formed.
The logic is straightforward once you see it from the market's side. Suppose a race has a 2/1 favourite and you back a rival at 8/1. The favourite is then withdrawn at the start. Your 8/1 shot now faces a much weaker field — its true chance of winning just improved substantially, but you're holding a price that was set when the favourite was still running. Without a correction, everyone holding 8/1 tickets would be sitting on value the bookmaker never intended to offer, through pure luck.
Rule 4 is that correction. Rather than voiding and re-striking every bet, the industry applies a standard deduction to winnings, scaled to how big a chunk of the market the withdrawn horse represented.
One thing worth being clear about, because it's the most common misunderstanding: the deduction comes off your winnings, never your stake. A 25p Rule 4 doesn't mean you lose 25% of your money. It means each £1 of profit becomes 75p. Your stake is returned in full as normal when you win.
The Rule 4 deduction table
The deduction depends on the odds of the withdrawn horse at the time it was taken out — not the odds of the horse you backed.
| Price of non-runner | Deduction per £1 of winnings |
|---|---|
| 1/9 or shorter | 90p |
| 2/11 to 2/17 | 85p |
| 1/4 to 1/5 | 80p |
| 3/10 to 2/7 | 75p |
| 2/5 to 1/3 | 70p |
| 8/15 to 4/9 | 65p |
| 8/13 to 4/7 | 60p |
| 4/5 to 4/6 | 55p |
| 20/21 to 5/6 | 50p |
| Evens to 6/5 | 45p |
| 5/4 to 6/4 | 40p |
| 8/5 to 7/4 | 35p |
| 9/5 to 9/4 | 30p |
| 12/5 to 3/1 | 25p |
| 16/5 to 4/1 | 20p |
| 9/2 to 11/2 | 15p |
| 6/1 to 9/1 | 10p |
| 10/1 to 14/1 | 5p |
| Over 14/1 | No deduction |
Individual bookmakers publish their own versions of this table and the band boundaries can differ by a fraction here and there, so check your book's own scale if a settlement looks off by a penny or two. The shape is always the same.
A worked example
You have £10 win on a horse at 8/1. Before the off, the 2/1 second favourite is declared a non-runner. From the table, a 2/1 withdrawal sits in the 9/5 to 9/4 band: 30p in the £.
Without the non-runner:
- Winnings: £10 × 8 = £80
- Returned stake: £10
- Total: £90
With the 30p Rule 4:
- Winnings: £80 − (£80 × 0.30) = £56
- Returned stake: £10 (untouched)
- Total: £66
Effectively you got paid at 5.6/1 instead of 8/1. Annoying, but remember what you got in exchange: the horse most likely to beat yours didn't run.
When Rule 4 applies — and when it doesn't
Rule 4 applies to bets struck at fixed prices before the withdrawal, in a market where a new market wasn't formed afterwards.
If a horse is withdrawn early enough, bookmakers will often reform the market — pull the old prices, reprice the race without the withdrawn horse, and start again. Bets placed after the reformation are at the new, tighter prices and carry no deduction from that withdrawal. Bets placed before it still get the Rule 4.
A few other cases:
- Starting price (SP) bets placed after the withdrawal are settled at the returned SP with no deduction — the SP already reflects the smaller field.
- Multiple withdrawals stack. Two non-runners at 10p each means a 20p total deduction. But the total is capped at 90p in the £, however many horses come out. You always get at least your stake back plus 10% of nominal winnings.
- Each-way bets: the deduction applies to the winnings of both the win part and the place part.
- Ante-post bets are the big exception, covered below.
Some bookmakers also waive the smallest deduction as a concession — you'll see "no 5p Rule 4" offers around the big festivals, which is a genuine (if small) freebie.
Rule 4 and ante-post betting
Rule 4 generally does not apply to ante-post bets — bets struck days, weeks or months before final declarations. Sounds good, until you learn the trade-off: if your own horse doesn't run, an ante-post bet is simply lost. Not voided, lost, the same as if it finished last.
That trade — no Rule 4 deductions, but no refund on non-runners — is the entire risk structure of ante-post betting. The exception is when a bookmaker offers Non-Runner No Bet (NRNB), common on the spring festivals. Once a race goes NRNB, stakes on non-runners are refunded, and in return bookmakers reserve the right to apply Rule 4-style deductions again. There's no free lunch anywhere in this market.
Why Rule 4 matters more than it looks
Most punters treat Rule 4 as background noise, a fact of life like the weather. But it interacts with value in a way worth understanding.
When you take an early price on a horse, you're taking a view against the market as it stands — including every horse currently in it. Part of what makes an 8/1 price attractive might be a wobbly favourite that's a doubtful runner. If that favourite comes out, your 8/1 becomes 8/1-minus-a-hefty-deduction on a race it might now win anyway... but the deduction is standardised, and standardised corrections are blunt. Sometimes the table over-corrects, sometimes it under-corrects.
The place market makes this sharper. In a race that loses a runner, the field size can drop through a place-terms boundary — a 8-runner race becomes a 7-runner race, and suddenly the each-way terms pay two places instead of three. Your each-way bet keeps its Rule 4 deduction and gets settled on meaner terms. Field size boundaries are one of the quiet places bookmakers make their margin, and they're covered in detail in our guide to how many places bookies pay.
If you compare prices across bookmakers as a habit — which is the whole point of vibeodds — it's worth knowing that after a well-fancied withdrawal, the books reprice at different speeds. The odds you see in the minutes after a market reforms are often the loosest of the day.
Frequently asked questions
Does Rule 4 take money from my stake?
No. Winnings only. If your bet loses, Rule 4 is irrelevant to you entirely.
How do I know a Rule 4 was applied?
Your bet settlement will show it, usually as "R4 20p" or similar. The deduction amount is also announced with the race result wherever official returns are published.
What if two horses are withdrawn?
The deductions add together, capped at 90p in the £ total.
Does Rule 4 apply to bets on the exchange?
Betfair applies its own reduction factors on the exchange win market rather than the Tattersalls table, and recalculates place reductions differently. Same principle, different arithmetic.
Does it apply to my place bet too?
Yes. On an each-way bet the deduction hits the winnings of both halves.
Can a Rule 4 be more than 90p?
No. 90p in the £ is the ceiling regardless of how many horses come out or how short they were.
The non-runner was 16/1 — why was there still a deduction?
The deduction is based on the price at the time of withdrawal, not the morning price. A 16/1 shot that was backed into 14/1 or shorter before being pulled out lands in a deduction band.
Is Rule 4 the same at every bookmaker?
Nearly. The standard Tattersalls table is the reference, but bands and rounding can vary slightly, and some books waive the 5p deduction as standard. Check the racing rules page of whichever book settled your bet.