What is Rule 4?
Rule 4 is the industry-wide rule that adjusts your bet's price when a horse you didn't back is withdrawn after the market opens. The deduction reflects how much shorter the field has become — because removing a fancied non-runner makes every other horse more likely to win, the bookmaker takes some of your potential winnings as a Rule 4 deduction. The amount is set by the non-runner's SP at the time of withdrawal: 5p per pound at very short prices, up to 90p+ for last-minute favourite withdrawals.
Your bet, before Rule 4
What price you took. Type fractional (5/1), decimal (6.00) or American (+500).
= 6.00 decimal
Add a stake to see the cash difference, or leave blank to compare just the new odds.
Rule 4 deduction
The pence-per-pound the bookmaker deducts from your winnings because a non-runner was withdrawn after you placed the bet. The amount is set by industry rules based on the non-runner's SP — common values are 5p, 10p, 25p and 40p.
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Frequently Asked Questions
Common questions
- Rule 4 (sometimes "Tattersalls Rule 4") is an industry-wide rule that reduces the odds on your bet when a horse is withdrawn from the race after the market opens but before the off. The deduction reflects the fact that the field is now smaller — every remaining runner has a higher chance of winning, so the bookmaker recovers some of the price they originally offered.
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