Rule 4 Deductions in Greyhound Racing: What You Need to Know

When a Dog Is Withdrawn and Your Bet Shrinks

You’ve backed a greyhound at 6/1 in a Derby heat. Ten minutes before the race, one of the other runners is withdrawn — an injury in the parade ring, a vet’s decision, or a trainer pulling a dog. The remaining five runners are now competing for the same race, and the odds have shifted because the field is weaker. Your bet still stands, but the bookmaker applies a deduction to your potential winnings. That deduction is called Rule 4.

Rule 4 is one of those mechanisms that every greyhound punter encounters eventually but few fully understand until it reduces their payout for the first time. This article explains what it is, how the deduction scale works, and what it means for your Derby betting.

What Is Rule 4 and Why Does It Exist

Rule 4 — formally Tattersalls’ Rule 4(c) — is a standardised mechanism for adjusting bet payouts when a runner is withdrawn from a race after the betting market has been formed. It exists because a withdrawal changes the competitive dynamics of the race: with one fewer runner, the remaining dogs each have a higher chance of winning, which means the original odds no longer accurately reflect their probability. Without Rule 4, punters who had already backed one of the remaining runners at the original odds would receive an unfairly generous payout relative to the actual risk.

The rule applies only to bets placed at fixed odds before the withdrawal occurs. If you placed your bet after the withdrawal was announced and the market had adjusted, Rule 4 does not apply because the price you took already reflected the smaller field. Similarly, bets at starting price (SP) are unaffected because the SP is determined at the off, when the final field is known.

In greyhound racing, Rule 4 situations arise less frequently than in horse racing — a six-dog race has fewer opportunities for withdrawals than a sixteen-runner handicap. But when they do occur, particularly in a high-profile event like the Greyhound Derby, the deductions can be substantial because the withdrawn dog often had a realistic chance of winning, which redistributes significant probability across the remaining field.

The rule is not optional. Bookmakers are required to apply Rule 4 deductions when the conditions are met, and the deduction percentage is determined by the withdrawn dog’s price at the time of withdrawal, not by any subjective assessment of its chances. This standardisation ensures consistency across the industry — the same deduction applies whether you bet with Bet365, Paddy Power, or a high-street independent.

If you bet on the withdrawn dog itself, your bet is void and your stake is returned in full. Rule 4 only affects bets on the remaining runners.

The Deduction Scale: How Much Comes Off Your Winnings

The Rule 4 deduction is expressed as pence in the pound and is determined by the odds of the withdrawn runner at the time of its withdrawal. The shorter the withdrawn dog’s price, the larger the deduction — because a shorter price means the dog was more fancied to win, and its removal redistributes more probability to the remaining runners.

The standard scale runs as follows: if the withdrawn dog was priced at 1/9 or shorter (an extremely strong favourite), the deduction is 90p in the pound. At 2/11 to 2/17, it’s 85p. At 1/4 to 1/5, it’s 80p. At 3/10 to 2/7, it’s 75p. At 2/5 to 1/3, it’s 70p. At 8/15 to 4/9, it’s 65p. At 8/13 to 4/7, it’s 60p. At 4/5 to 4/6, it’s 55p. At 20/21 to 5/6, it’s 50p. At evens to 6/5, it’s 45p. At 5/4 to 6/4, it’s 40p. At 8/5 to 7/4, it’s 35p. At 9/5 to 9/4, it’s 30p. At 12/5 to 3/1, it’s 25p. At 16/5 to 4/1, it’s 20p. At 9/2 to 11/2, it’s 15p. At 6/1 to 9/1, it’s 10p. At 10/1 to 14/1, it’s 5p. Beyond 14/1, the deduction is zero — the withdrawn dog was enough of an outsider that its removal doesn’t materially change the remaining runners’ chances.

In practice, this means the deduction hits hardest when a favourite or second favourite is withdrawn. If the 6/4 market leader in a Derby heat is pulled out after you’ve backed another dog at fixed odds, a 40p deduction applies to your winnings. On a £10 bet at 5/1 that wins, your gross profit would normally be £50 — but after the 40p-in-the-pound deduction, you receive £30 profit instead. Your stake is always returned in full; the deduction applies only to the profit portion.

The deduction bites especially hard on shorter-priced selections. If you backed the 2/1 second favourite and the 6/4 favourite is withdrawn, your 2/1 bet still stands but with a 40p deduction. Your £10 bet produces £20 gross profit minus £8 deduction, netting £12 profit. At longer odds, the absolute deduction is larger but the proportional impact on your total return is smaller, because the gross profit baseline is higher.

Rule 4 in the Greyhound Derby: Practical Scenarios

Withdrawals in the Greyhound Derby most commonly occur in heats and semi-finals rather than the final itself. A dog might pick up a minor injury in the warm-up, fail a pre-race veterinary inspection, or be withdrawn by a trainer who judges it not fit to run. In a knockout competition where each round involves six runners, even a single withdrawal reduces the field to five — and in the Derby, where every runner is typically fancied to some degree, the withdrawn dog’s price is often short enough to trigger a meaningful deduction.

Consider a Derby semi-final where six dogs are declared and the betting market is formed. You back dog A at 3/1 before the race. Thirty minutes before the off, dog D — the 7/4 second favourite — is withdrawn after a paddock inspection. Rule 4 applies: the deduction for a 7/4 withdrawal is 35p in the pound. If dog A wins, your £10 bet at 3/1 produces £30 gross profit. The 35p deduction reduces that by £10.50, giving you £19.50 profit plus your £10 stake returned. Not catastrophic, but a noticeable reduction — especially if you had a larger stake.

The impact on accumulator bets is compounded. If you have a four-fold accumulator across four Derby heats and one of those heats has a Rule 4 deduction, the reduced payout from that leg carries forward into the next leg’s stake calculation. Across a multi-leg bet, even a modest 10p deduction on one leg can knock a meaningful amount off the final return. This is worth considering when you build accumulators on Derby night — the risk of at least one withdrawal across a full card is not trivial.

Each-way bets are also subject to Rule 4. The deduction applies to both the win and place portions of the bet. If your each-way selection wins or places, both halves of the payout are reduced by the applicable deduction rate. On a £10 each-way bet (£20 total), a 15p-in-the-pound deduction on a winning bet reduces both the win profit and the place profit, effectively taxing both legs of the wager.

One protective measure: if you bet with a bookmaker that offers Best Odds Guaranteed and the SP after the withdrawal is higher than your taken price, the BOG upgrade may partially or fully offset the Rule 4 deduction. The two mechanisms operate independently — BOG raises your settlement price while Rule 4 reduces the profit — but the net effect can leave you close to where you’d have been without the withdrawal. This is another reason to favour BOG bookmakers for Derby betting, as they provide a natural hedge against the Rule 4 drag that withdrawals introduce.

Rule 4 Is a Cost of Doing Business — Plan for It

Rule 4 deductions are not a bookmaker scam or a hidden fee. They’re a fair adjustment that reflects the genuine change in competitive dynamics when a runner is removed from a race. The mechanism protects the integrity of fixed-odds betting by ensuring that prices remain connected to actual probabilities, even when those probabilities shift at the last minute.

For Derby punters, the practical response is to factor Rule 4 as a known possibility rather than an unwelcome surprise. It won’t apply to most of your bets — withdrawals in greyhound racing are relatively rare. But when it does apply, particularly in a heat where a well-fancied dog is pulled out, the deduction is real and it reduces your return. Knowing the scale, understanding how it affects each-way and accumulator bets, and using BOG as a partial offset puts you in the best position to absorb the impact without it derailing your strategy.