What is Rule 4 in Horse Racing?

I am often surprised by how few punters understand specific rules in racing betting. In horse racing and greyhound racing, Rule 4 is applied now and then, yet bettors don’t understand why their profit has been reduced. Today, I aim to fix that.

In basic terms, Rule 4 is an industry-standard deduction made on a dog or horse in races with a non-runner. It is applied if the runner is withdrawn after the final declarations and IF you have taken a fixed odds price.


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It gets the name “Rule 4” because is was the fourth rule in the list created by Tattersall’s, one of the organisations involved in the codification and governing of horse racing in Ireland and the UK.

The Rule 4 deductions are made from the Starting Price (SP) of a horse when a runner gets withdrawn just before the start of a race, and there is no time for bookies to create a new market.

Why Do Bookmakers Impose Rule 4 Deductions?

The reason is fairly obvious when you analyse it. Bookies implement Rule 4 after a late withdrawal because, in theory, it makes it easier for other runners to win the race.

Technically, a horse has a better chance of winning if up against six competitors rather than seven, for example. In theory, there are certain races where it would be possible to make a profit by backing all runners if there is a late withdrawal or two.

In a three-horse race, for example, horse #1 is the 1.30 favourite, horse #2 is 3.75, and horse #3 is 51.00. The overround is 5.54%, so the bookie is happy.

If horse #2 was withdrawn late on and Rule 4 didn’t come into play, the bookie would be in dire straits because the punter would have an advantage of over 20%. You could easily place a £100 bet on horse #1 and a £5 bet on horse #2 and have a guaranteed profit of £25 coming your way.

A more likely example is if you back the second favourite at odds of 4.00. If the odds-on favourite (at odds of 1.80) withdraws late on, your bet suddenly offers sensational value. If the bookies knew early on that the favourite would be out of the race, there is no way on Earth you would get odds of 4.00 on your horse!

Ultimately, Rule 4 only applies when the final declarations for a race are made; this usually happens 24-48 hours before the race. I have read some articles online which state that you lose your stake if you back a non-runner. This is simply not true; your bet is void in that case and your money is returned.

What Are The Rule 4 Deductions?

There are set Rule 4 deduction rules in UK racing that all bookmakers must adhere to. The exact amount deducted depends on several factors. For example, it is easier for the second favourite to win if the favourite is withdrawn than if an outsider withdraws. Therefore, there are different deductions depending on the price of the withdrawn horse.

For example, if the withdrawn horse was available at odds of 1.11 when pulled out of the race, 90% of your profit is taken away. Therefore, if you stand to win £20 from your bet, but if the horse at 1.11 odds withdraws at the last minute, you only make a £2 profit if your horse wins!

I have included the full table of Rule 4 deductions below. The odds are in decimals, and the deduction is in percentage terms rather than the 90 pence in the pound tables seen elsewhere. For instance, a deduction of 65p in the pound is 65%, and odds of 2.75 equate to 7/4. You will notice gaps in the odds; that is because they are SP odds.

Odds of Withdrawn Horse in Decimal FormDeduction in Percentage Terms
1.01 – 1.1190%
1.12 – 1.1885%
1.20 – 1.2580%
1.29 – 1.3075%
1.33 – 1.4070%
1.45 – 1.5365%
1.57 – 1.6260%
1.66 – 1.8055%
1.83 – 1.9550%
2.00 – 2.2045%
2.25 – 2.5040%
2.60 – 2.7535%
2.80 – 3.2530%
3.40 – 4.0025%
4.20 – 5.0020%
5.5 – 6.5015%
7.00 – 10.0010%
11.00 – 15.005%
16.00+No Deduction

As you can see, the deduction increases by 5% in each price range. Going back to the hypothetical example at the beginning; if you bet £20 on the horse at odds of 3.75, you would make a profit of £55 if it won. However, if the 1.30 favourite withdraws late on, your profit drops by 75% when Rule 4 is implemented.

Therefore, the odds on your horse fall from 3.75 to around 0.93 or 0.94. It is an extreme example because you would love to get this kind of odds against a 51.00 outsider!

Can I Profit from Rule 4?

In theory, you can if you carefully select the race. When you think about it, if you back a non-favourite in any race, you are suggesting that the favourite is not worth backing. In such instances, Rule 4 costs you because it strips away the value you worked hard to find.

Matt Bisogno, a well-known tipster, has developed something he calls the Reverse Rule 4 method. Basically, you find a favourite in a handicap race at odds of 3.00 or shorter and try to find a few pieces of form or other data that count against this horse.

Then, find one or two horses in that race worth selecting against the favourite. If the favourite withdraws, your horse’s odds may be cut, but the likelihood of it winning also increases. More importantly, you have identified a false favourite and a hidden fancy at a juicy price.

Overall, having a Rule 4 deduction go against you is a pain, but it is part and parcel of horse racing. To be fair, it doesn’t happen very often, and when it does, I can’t fault the fact that there is protection in place for oddsmakers. You can only hope that it doesn’t hurt your bank balance too much!