Starting Price (SP): What SP Means in Horse Racing and How It Is Set

Every horse in every race run in Britain ends up with an official price, the one it was trading at as the race started. That is the starting price, and it is what SP stands for. If you put a bet on without fixing the odds, it is the price you are paid at.

Most of the time it sits quietly in the background. It matters the moment you compare it with the price you could have taken earlier, or when a result looks smaller than you expected.

What does SP mean in horse racing?

The short answer to what does SP mean in horse racing is this: the SP is the market’s final word on each runner. Before a race, prices move all day as money comes in and news breaks. The SP freezes that movement at the off and records one price per horse.

It has two jobs. It settles bets struck without a price, which in a betting shop are simply the slips with no odds written on them. And it gives a common reference point for everyone else: the result of every race lists each horse with its SP, so the favourite, the outsiders and the size of a shock are all on the record.

A horse that “went off 9/2” was returned at an SP of 9/2. A horse that won “at 33/1” was a 33/1 chance on the official return, even if some people had backed it earlier at bigger odds.

How the starting price is worked out

The SP isn’t one bookmaker’s price. In Britain, the method is set by the Starting Price Regulatory Commission, an independent body whose job is to make sure the returned price reflects what was available to bettors at the off. It doesn’t set any price itself. It sets the rules, and independent validators check that the returns follow them.

For a long time the SP came entirely from the bookmakers standing on the racecourse. That changed after 2020. A review by the Commission found that only a small share of British racing bets was being struck on course, so an SP built only from the course no longer reflected the real market. Since 2022 the starting price has been compiled mostly from prices offered by off-course bookmakers, with an element that reflects the on-course market.

The calculation takes a sample of prices for each horse and uses a middle value, close to the median. In rough terms, the sampled prices are lined up from longest to shortest, the list is cut in half, and the SP is the shortest price in the longer half. So the SP is not the best price available at the off, and it is not the worst. It is a fair middle.

That is worth knowing for one reason in particular. If you wait for SP, you are taking the market average, not the top of the market. Someone who shopped around at the off may well have got a point or two more than the SP on the same horse.

Taking a price or leaving it to SP

Every bet on a horse race is struck one of two ways. You either take the price on offer when you bet, or you leave it to the SP.

Take a price and you know exactly what the bet will pay. Say you back a horse at 6/1 in the morning with £10, and by the off it has been backed into 9/2. Your bet still pays 6/1, which is £70 back if it wins. Someone who left the same bet to SP gets 9/2, which is £55.

It works the other way too. If your 6/1 horse drifts to 10/1 because nobody fancies it, the fixed-price bet is still paid at 6/1, and the SP player gets the bigger price.

So the choice comes down to whether you think the price will shorten or drift, and nobody knows that for certain. A reasonable habit is to take a price when you have a firm view and the odds look fair, and to leave it to SP when you are betting late and simply want the market price.

There is one practical point. In a betting shop, a slip without a price is settled at SP automatically. If you want the price on the board, write it on the slip or ask for it at the counter when you pay.

Best odds guaranteed and the SP

Many bookmakers offer best odds guaranteed on races on the day. The offer removes the gamble described above: if you take a price and the SP turns out bigger, you are paid at the SP instead.

Take a £10 win bet at 5/1 on a horse that drifts and goes off at 7/1. Without the offer, you are paid at 5/1, which returns £60. With best odds guaranteed, you are paid at 7/1, which returns £80. If the horse shortens instead, you keep your 5/1.

The terms differ between firms: which races are covered, what time the offer starts, and whether there is a limit on the extra paid. It is worth reading the conditions where you bet, because the offer only works if it applies to the race and the bet type you placed. Bets struck well in advance, before the day of the race, normally sit outside it; the ante-post guide covers those.

The SP in each way bets and multiples

An each way bet at SP is settled on the SP for both halves. The win part pays at the SP, and the place part at the usual fraction of it. A horse returned at 10/1 in a race paying 1/5 of the odds pays 2/1 for the place.

In a multiple, each leg is settled at its own price, whether that is a price you took or the SP. It is quite normal to have a double where one horse was taken at a fixed price and the other left to SP. The bet is only fully known once the second race is over.

A small example of settling at SP by hand: £8 on a horse that wins and is returned at 11/4. Turn 11/4 into a decimal, 3.75, and multiply by the stake. The bet returns £30, of which £22 is profit. The bet calculator does the same sum for any bet, and the odds converter turns any SP into a decimal.

The SP and Rule 4

When a horse is withdrawn at the last moment, the other runners were priced against a rival that is no longer in the race. Rule 4 corrects that by making a deduction from the winnings on bets struck at a fixed price.

Bets at SP normally escape it. After a withdrawal the market re-forms, and the new SP already reflects the smaller field, so there is nothing to correct. The exception is a withdrawal so late that there is no time for a new market to form, for example a horse withdrawn at the start. In that case SP bets can carry a Rule 4 deduction as well. The Rule 4 page has the table and the worked examples.

Using the SP to check your own prices

The SP has a second life as a yardstick. Because it is the market’s closing view, some bettors keep a record of the price they took against the SP each horse was returned at. If the prices you take are usually bigger than the SP, you were getting in before the market moved your way. If they are usually smaller, you were paying for impatience.

It is a useful habit for one reason: it separates the price from the result. A losing horse taken at 8/1 that went off at 5/1 was still a well-timed bet, and a winner taken at 3/1 that went off at 5/1 was a poorly timed one that happened to come in. Over a few dozen bets, the comparison says more about your timing than the wins and losses do.

It is only a yardstick, not a verdict. The SP is a middle value across a sample of firms, so beating it by a fraction is not a meaningful difference, and it says nothing about whether your horses were good bets in the first place.

When your own horse doesn’t run

If the horse you backed is withdrawn before the race, it has no SP, and the bet is treated as a non-runner. A single on it is void and you get your money back. In a multiple, that leg drops out and the rest of the bet carries on. The one big exception is a bet struck ante-post, before the final declarations, where the stake is normally lost if the horse doesn’t run.

SP compared with the tote

The tote is a separate system, and its dividend is not the same thing as the SP. A tote dividend is worked out from the pool of money staked with the tote on that race, after a deduction. The SP is compiled from bookmakers’ prices.

The two often land close together, but not always. A horse that was heavily backed with the bookmakers but ignored in the tote pool can pay more on the tote than its SP suggests, and the reverse happens too. Neither is right or wrong. They measure different markets.

Reading the SP in a result

Once you know what does SP mean in horse racing, the result of a race reads more easily. Each horse’s SP is printed beside its name, and the favourite is marked. A result with a 25/1 winner and the 6/4 favourite unplaced is a bad day for favourite backers, and the SPs tell you that at a glance.

The SPs also give a quick way to judge a race after the event. Add up the chances the SPs imply across the field and the total comes to more than 100%, because the bookmakers’ margin is built into every price.

One quirk is worth a mention. In a two-runner race, the SPs can look strangely short on both horses, because the margin has only two prices to sit in. It is the same arithmetic as a full field, just with nowhere to hide.