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What Is A Rule 4 Deduction? (How It Works)

What Is A Rule 4 Deduction? (How It Works)

Navigating the world of horse racing bets can be daunting for the uninitiated, with terms like Rule 4 Deduction creating additional confusion. Yet, this rule can have a big impact on a bettor's experience, so having a solid understanding of it can be helpful. 

In this Mega Reel blog post, we will unravel the mystery of Rule 4 Deductions, shedding light on what it is, its impact on bets, and why it's a pivotal part of horse racing betting. 

What Is A Rule 4 Deduction?

At its core, a Rule 4 Deduction comes into play under the Tattersalls Rule of Racing, specifically Rule 4(c), when a horse is unexpectedly withdrawn from a race post-bet placements. This rule adjusts the odds for the remaining contenders, reflecting the reduced field and the resulting enhanced chance of each horse winning. 

The adjustment is quantified as a deduction from bettors' winnings, calculated in pence per pound, ensuring a balanced payout system despite the changing odds. 

How Does A Rule 4 Deduction Work?

Imagine placing a bet, and suddenly, a contender is out. Instantly, the dynamics change due to the remaining horses having an increased chance of winning because there's now less competition. Rule 4 ensures that the payouts adjust to this new reality, preventing disproportionate winnings based on the altered odds. 

The deduction rate correlates with the odds of the withdrawn horse; the better the odds, the larger the deduction. For example, for every pound you win, if the deduction is 10p, and you were to win £10, you'd actually receive £9. The cap for this deduction stands at 90p, safeguarding at least 10% of your potential winnings, regardless of the number of withdrawals. 

Where Does Rule 4 Money Go?

A common misconception is that the deducted amount lines the pockets of bookmakers. In reality, it simply recalibrates the payout to ensure fairness in the betting landscape, reflecting the true odds post-withdrawal. 

It's not a profit mechanism for bookmakers but a fairness tool for bettors to ensure the odds reflect the reality of the event. 

Rule 4 FAQs

Does Rule 4 Apply To Each Way Bets?

Rule 4's reach extends to all bet types, including win and each-way bets, ensuring that the adjustment is universally applied to all affected bets.

Does Rule 4 Apply To Exchanges?

When it comes to betting exchanges, the application of Rule 4 deductions varies compared to traditional bookmakers. The odds are usually not adjusted after a withdrawal. However, if a horse is withdrawn and it was matched at 14/1 or under, the exchange may reduce the winnings of the remaining bets in the market. 

What Is The Maximum Rule 4 Deduction?

No matter how many horses are withdrawn from the race or the odds of the withdrawn horses, the maximum deduction is 90p on the pound. This ensures that bettors always retain at least 10% of their original potential winnings. 


Grasping what the Rule 4 Deduction is and what it means for the bettor is a significant aspect of horse racing betting. It's not just about understanding that there is a deduction if a horse is withdrawn but recognising their role in maintaining fairness and balance for bookmakers and punters. 

As always, please gamble responsibly.