Rule 4 Deduction Table — Full Scale of Deductions in Horse Racing

One table governs every Rule 4 deduction in British horse racing. It has not changed in structure since the Tattersalls Committee last revised it, and every bookmaker in the UK — online or on-course — applies the same scale. The deductions run from 5p in the pound for long-priced non-runners to 90p in the pound for odds-on favourites, with a series of fixed steps in between. No negotiation, no bookmaker discretion, no exceptions.

The scale is officially known as Tattersalls Committee Rule 4(c), and it exists to protect the integrity of the betting market when a withdrawal changes the odds. Without Rule 4, a non-runner would shorten the remaining field’s prices, but bettors who took their price before the withdrawal would collect at odds that no longer reflected reality. The deduction corrects for that gap — imperfectly, but consistently. The same table applies whether the non-runner is scratched at Ascot or Ayr, in a Group 1 or a seller, on a Tuesday evening or a Cheltenham Saturday.

One table, every deduction. Here it is, row by row.

The Complete Rule 4 Deduction Table

The Rule 4 deduction is determined by the price of the withdrawn horse at the time it is removed from the race. The deduction is expressed in pence per pound of profit — not per pound of stake. Your stake is always returned in full on a winning bet; it is only the profit that is reduced.

This is the complete Rule 4 deduction scale as published by the Tattersalls Committee and applied by all licensed bookmakers in Great Britain. The scale has remained unchanged in its current form since the last revision in 2010, though the underlying framework dates back to the original Tattersalls Rules on Betting established in 1886.

Notice the compression at the short end of the scale. Between odds-on and evens — a relatively narrow price range — the deduction jumps from 45p to 90p. This is because short-priced non-runners have the greatest impact on the remaining field. When a 1/3 favourite is withdrawn, the market shifts dramatically; the deduction reflects that shift. At the other end, a horse priced at 12/1 barely moves the market when it is scratched, so the deduction is a modest 5p. Beyond 14/1, the impact is considered negligible and no deduction applies at all.

How to Read the Table — Odds to Deduction in Seconds

Using the table takes seconds once you know the process. You need two numbers: the price of the non-runner at the time of withdrawal, and the profit from your winning bet.

Step one: find the non-runner’s price in the left column. This is the price at the time the horse was officially removed from the race — not the price it was trading at earlier in the day or the overnight price. Bookmakers are required to use the withdrawal price, which is typically the last price the horse was offered at before it was scratched.

Step two: read across to the deduction. That figure — expressed in pence — is the amount deducted from every pound of your profit. A 25p deduction means you lose 25p for every £1 you would have won. On £100 of profit, the deduction is £25. On £40 of profit, the deduction is £10.

Step three: calculate your adjusted return. Take your original profit, subtract the deduction, and add your stake back. Your stake is never touched by Rule 4 — only the profit is reduced. If you staked £10 on a horse at 6/1 and the Rule 4 deduction is 25p, your gross profit was £60. The deduction is £60 × 0.25 = £15. Your adjusted profit is £45, and your total return is £55 (£45 plus your £10 stake).

The framework behind this scale was established by the Tattersalls Committee in 1886, originally designed to settle disputes between on-course bookmakers and punters at Newmarket. The committee codified twelve rules governing betting settlement, of which Rule 4 became the most widely known. The core principle has not changed across multiple revisions: deductions are fixed, transparent, and the same for every bookmaker.

Edge Cases — No Deduction, Maximum 90p, Multiple Non-Runners

Three edge cases come up regularly, and each catches bettors who know the standard table but have not encountered the exceptions.

The first is the no-deduction threshold. Any non-runner priced over 14/1 does not trigger a Rule 4 deduction. The horse is simply removed from the field, and all remaining bets are settled at full odds. This means that in big-field handicaps where outsiders are scratched, your payout is unaffected. The logic is that a horse at 16/1, 20/1, or 33/1 had such a small implied chance of winning that its removal does not meaningfully change the remaining runners’ probabilities. In practice, this threshold means that most non-runners in 20-plus runner handicaps — where a large proportion of the field is priced above 14/1 — produce no deduction at all.

The second edge case is the maximum 90p cap. No matter how short the non-runner’s price, the deduction cannot exceed 90p in the pound. A horse at 1/9 triggers a 90p deduction. A horse at 1/20 also triggers a 90p deduction — the same rate, despite being far more dominant in the market. The cap exists because a 100p deduction would eliminate the entire profit, which the Tattersalls Committee deemed unreasonable. Even when a prohibitive favourite is scratched, bettors retain at least 10p of every pound of profit. It is a small consolation, but it is the floor.

The third edge case is multiple non-runners in the same race. When two or more horses are withdrawn, each triggers its own Rule 4 deduction, and the deductions are cumulative. If the first non-runner triggers a 25p deduction and the second triggers a 15p deduction, the combined deduction is 40p. However, the cumulative total is capped at 90p. No combination of non-runners can push the total deduction beyond the maximum. In a five-runner race where three horses are withdrawn — leaving just two runners — the cumulative Rule 4 might be 90p, but it will never exceed it.

One further nuance: when multiple non-runners produce a cumulative deduction that pushes the total close to or at the 90p cap, some bettors question whether the race should have been voided entirely. The answer under current rules is no — as long as at least two horses go to post, the race stands and bets are settled with Rule 4. The only scenario that voids all bets outright is a walkover (one horse left) or an abandoned race. Two runners with a 90p deduction is still a valid race, and the 10p of profit you retain is all the rules guarantee.