Rule 4

Rule 4 (Deduction) is a horse racing betting rule used by bookmakers to adjust payouts when a horse is withdrawn (non-runner) after bets have been placed. It ensures that remaining bets are fairly adjusted based on the impact of the withdrawn horse.

• If a strong contender is withdrawn from a race, the odds for the remaining horses shorten because their chances of winning improve. To compensate, bookmakers apply a deduction to winnings based on the withdrawn horse's odds.

• 1.29 or shorter → 90p per £1 deducted
• 1.30 - 1.49 → 85p per £1 deducted
• 1.50 - 1.99 → 80p per £1 deducted
• 2.00 - 2.99 → 50p per £1 deducted
• 3.00 - 3.99 → 40p per £1 deducted
• 4.00 - 5.99 → 30p per £1 deducted
• 6.00 - 9.99 → 20p per £1 deducted
• 10.00 - 14.99 → 10p per £1 deducted
• 15.00 or higher → No deduction

You place a bet on Horse A at 5.00. A competing horse is withdrawn, and Rule 4 applies at 30p per £1. If your horse wins, instead of being paid at 5.00 odds, the payout is reduced based on the deduction.

Rule 4 deductions only apply to winning bets and are designed to maintain fairness in betting markets when race conditions change.