Why Does One Race Cost More to Bet On Than the Next?

The dearest race on a card can cost four times as much to bet in as the cheapest race on the same card, and nothing about the bookmaker changes between them. What changes is how many horses are in the race.

At the Ebor Festival in August the cheapest race to bet in carried a charge of 11.0% over a fair book. The dearest carried 43.5%. Same meeting, same four days, same firms taking the bets.

That is a wider spread than the one between the cheapest and dearest festivals of the entire summer. Which race you pick on a card matters more than which card you pick.

It happened at every meeting we measured, without exception. At Royal Ascot the dearest race of the week charged 6.2 times what the cheapest did, and at Glorious Goodwood 5.0 times. Every time, the same two kinds of race sat at the two ends.

The cheapest race is always small, the dearest always big

At all 9 festivals, the cheapest race of the week had between three and nine runners. The dearest had between fifteen and thirty.

The reason is mechanical. A bookmaker prices every runner and takes a slice on each. Add runners and you add slices, and the ones at the back of the market are the fattest: a horse at 66/1 is being marked as roughly a one-in-sixty-seven chance, and horses at that price win less often than that.

In a five-runner Group race there is nowhere to hide that sort of margin. Every horse is closely watched, the prices are compared, and any firm pricing them meanly is easy to spot. In a twenty-four-runner handicap there are a dozen horses that nobody is really pricing carefully, and that is where the charge accumulates.

So the spread inside a card is not the bookmaker treating the big race as special. It is arithmetic with more terms in it.

Sorted by runners, the pattern is almost mechanical

Here is every festival race we measured, grouped by how many runners went to post.

Three buckets, 269 races, and the charge close to triples from the top row to the bottom. There is very little noise in that relationship and it needs no interpretation.

By grade the picture is similar but weaker, which is itself informative.

Group and Listed races are cheaper than handicaps. But they are also smaller, and once you allow for field size most of the grade effect goes away. Group races are cheap because they are small, not because they are good.

That distinction matters if you are choosing a race. Do not look for the classy race. Look for the short field.

A word on all of this

None of these pages is a tip, and none describes a way to win. They describe what betting costs, which is a different and more reliable subject. If your betting has stopped being fun, BeGambleAware has free, confidential help, and the National Gambling Helpline is on 0808 8020 133.

Common questions

Which race on a card is cheapest to bet in?

Almost always the one with fewest runners. At all 9 festivals we measured, the cheapest race of the week had nine runners or fewer and the dearest had fifteen or more.

Why are big handicaps so expensive?

More runners means more prices, and the long-priced runners at the back of the market carry the heaviest charge. A big handicap has plenty of them.

Is a Group 1 better value than a handicap?

On average yes, but mostly because Group races have small fields. Pooled across 269 races, once field size is accounted for the difference by grade is much smaller than it first appears.

Does this vary by bookmaker?

The overall level does, a little. The pattern by field size does not: it comes from the structure of a betting market rather than from any one firm's policy.

What was the single dearest race you measured?

A thirty-runner handicap at Royal Ascot, at nearly half as much again as a fair book.