Back and Lay Horses on a Betting Exchange: From the Off to Settlement
A horse comes out, a price changes, an unmatched offer disappears. Here is what the rules do to a racing bet, with the sums.
On a horse racing betting exchange you back a horse at a price another user offered, or lay it and pay out if it wins. Orbit Exchange’s rules then decide what happens to that bet. An unmatched offer is cancelled when the race goes in-play unless it is marked “Keep”. In the win market, a withdrawn horse with a factor of 2.5% or more cuts the price of bets already matched. A dead heat usually cuts the stake. The race is settled on the result at the weigh-in. Below, each case with the arithmetic, on a made-up £85 at 11.0.
Backing a horse, laying a horse
A minute before the off, your £85 is matched at 11.0. Then one horse in the race is withdrawn, and the price you backed may no longer be 11.0.
First, the two sides. A back is a bet that the horse wins. A lay is the other side of that bet, taken from whoever backed it. On Orbit Exchange the back price is the blue one and the lay price the pink one; the interface text reads “To place a lay bet, click on the pink price next to the selection you’re interested in.” The lay slip is titled “Lay (Bet Against)”, and it carries the labels “Backer’s odds”, “Backer’s stake” and “Your liability”.
The interface also says “In a lay bet, you’d risk an amount the backer would naturally win.” and “For lay bets: potential profit = backer’s stake.” Same bet, two seats. How a back and a lay work goes through the slip in general, and what a thin market takes covers why the stake that fits is the one others offer at your price.
Eighty-five at eleven
Say you back £85 at 11.0. If the horse wins you collect £850; if it loses you are out £85. The layer on the other side has a liability of £850 and keeps your £85 if the horse loses. Commission comes off a net profit, after all of this (the commission page has the mechanism, and no rate is written here).
From the off to the result
A race has five stages that matter to a bet. Each has its own rule.
- Market loaded. Each horse is given a reduction factor, a percentage based on a forecast price.
- Before the off. An unmatched bet stays in the market as an offer until you cancel it. Prices and sums move all the time, “particularly just before a race or when a market is in-play”, so you may need to change the odds or the stake to be matched. If nobody matches it before the market closes or turns in-play, and it is not marked “Keep”, the money comes back.
- At the off. Orbit’s exchange rules void matched bets after the official off when a market not planned for in-play is not suspended in time. For a market planned for in-play that is neither suspended at the off nor turned in-play during the race, the bets are void from the official off, not the scheduled one. Unless the rules say otherwise, if the market is turned in-play later on purpose, bets matched after the off stand. An offer marked “At In-Play: Keep”, chosen in the bet manager, is not cancelled at the start, and the general principle is that a Keep bet is cancelled only if it is still unmatched when the market closes for the final time, with exceptions the rules reserve.
- Settlement. Individual race markets settle on “the official result at the time of the ‘weigh-in’ announcement”. Disqualifications and appeals that come later are disregarded.
- Void cases. An abandoned race, a walkover or a race not run on its scheduled day voids every bet on it, and so does a change of venue after the market was loaded. A change of surface leaves the bets standing.
The exchange aims to turn markets in-play at the off but does not promise to do it on the second. In-play bets are yours to manage, at all times. So the Keep option is a choice to make before the off.
When a horse is withdrawn
Orbit’s non-runner rule adjusts the odds on bets already matched when a horse is declared a non-runner. The adjustment is the reduction factor of the horse that left, applied to the rest of the field. Any horse listed at loading that does not come under starter’s orders counts as a non-runner. You can read each horse’s factor on the market’s info page, and a horse has a different factor in the win market and in the place market.
Matched bets on the withdrawn horse are void and the horse leaves the market. Now the rest.
In the win market, a factor of 2.5% or more reduces the traded price of matched bets on the remaining horses by the factor, and unmatched lay offers are cancelled, except those marked “Keep”. Under 2.5%, nothing is reduced and unmatched bets stay. The price never goes below 1.01, and the factors of the remaining horses are then adjusted to reflect their improved chance. As a rule, no factor applies to bets struck in-play. Take your £85 at 11.0 with a 12% withdrawal: 11.0 × (1 − 0.12) is 9.68, and the profit if the horse wins falls from £850 to £737.80.
Hypothetical. Profit if the horse wins, before commission, for four final reduction factors.
Show the data table
| Factor | Price | Profit |
|---|---|---|
| Under 2.5% | 11.0 | £850.00 |
| 12% | 9.68 | £737.80 |
| 20% | 8.8 | £663.00 |
| 40% | 6.6 | £476.00 |
The place market works on another base. The factor of every non-runner applies, even under 2.5%, and it cuts the potential winnings, not the traded price. The rules read “reductions will be made to the potential winnings on the bet only, and not the traded price.” Unmatched lay offers, except those marked “Keep”, are cancelled only from 4.0% up. On the same 12%, the £850 of potential winnings becomes £748.00, which is a revised price of 9.8.
Side note: “reduction factor” is a percentage, not a count of horses. Anyway.
One case more. After a late withdrawal judged important, which the rules put at a reduction of about 20% or more in the win market, Orbit reserves the right to cancel all lay “Keep” bets (in both the win and to-be-placed markets) before turning the market in-play; if it does not, lay “Keep” bets placed before the off and matched in-play stay at the original price.
Same percentage, different base
In the win market the factor cuts the price; in the place market it cuts the winnings. At 12% on £85 at 11.0 that is 9.68 against 9.8. Read which market your bet is in.
Place, each way and dead heats
A “to be placed” market pays a set number of winners. That number is the one in the market information, fixed from the runners known when the market was loaded. Once the market is open, further non-runners do not change it. If the number is equal to or greater than the number of runners, every bet in that market is void.
Each way is two bets. The win part is a win bet. The place part settles on the number of places and the fraction of the win profit stated in the market information, which the interface shows as “EW Terms: 1/{odds} odds, {places} places”. The sum is the win price minus one, times the fraction, plus one. At 1/4 on a horse at 19.0 it is (19.0 − 1) ÷ 4 + 1, so 5.5.
Dead heat is the third case.
Unless the rules or the market information say otherwise, the Dead Heat Rule applies where a market has more winners than expected. For each matched bet on a winner, the stake becomes “stake multiplied by (number of winners expected/number of actual winners)”, the winnings are paid on that reduced stake at the traded price, and the rest of the stake goes to the layers. So take a two-way dead heat for the win with £85 at 11.0: expected winners one, actual winners two, reduced stake £42.50, return £467.50, which is a net £382.50 against the £850 of a clean win, and the £42.50 left over of the original stake passes to the people who laid the horse.
Ante-post, in a few lines
In an ante-post market, all bets on a horse stand whether it runs or not. Some exceptions are about death and withdrawal. If a horse dies or is officially withdrawn, Orbit judges whether it was a “material runner”, broadly a horse with an approximate chance of winning of 8-10 per cent or better. If it was, every bet in the market struck between the death or notice and the suspension is void. If not, only the bets on that horse are. Non-runner reductions are not made to ante-post bets.
Who this suits
Best for a bettor who wants to name the price or lay a horse, and is happy to manage offers at the off. Not ideal if you want to leave an offer through the start without deciding whether to use Keep, or if you do not want to read the market information for places and each way terms.
These sums are arithmetic on made-up stakes and prices. They do not predict a race.
Who caps a stake sets exchanges against bookmakers, prediction markets are another place a price is quoted, and the odds converter turns decimals into other formats if you need it.
Questions a race raises
Can you lay a horse on a betting exchange?
Yes. A lay takes the other side of a back: it wins if the horse loses. The layer’s profit is the backer’s stake, and the liability is that stake times the price minus one. How a back and a lay work shows the slip.
What happens to my bet if a horse is withdrawn?
The matched bets on that horse are void and it leaves the market. Bets on the other horses can be cut by the withdrawn horse’s reduction factor. In the win market, 12% turns 11.0 into 9.68. The section on withdrawals has the sums.
What does At In-Play: Keep do on a race?
It is an option in the bet manager. A bet marked “At In-Play: Keep” is not cancelled when the market turns in-play, and stays while it is unmatched, up to the final close of the market. Orbit’s exchange rules reserve the right to cancel all lay “Keep” bets before the market turns in-play after a late withdrawal judged important, and, in exceptional cases, to cancel “Keep” bets to protect customers.
How is each way settled on an exchange?
The win part settles as a normal win bet. The place part settles on the number of places and the fraction of the win profit stated in the market information. At 1/4 on a horse at 19.0, the place price is (19.0 − 1) ÷ 4 + 1 = 5.5.
What happens in a dead heat?
In a dead heat, unless the rules say otherwise, the stake on a winner is cut to the stake times the winners expected over the winners actual. An £85 back at 11.0 in a two-way dead heat for the win becomes £42.50 and returns £467.50, a net £382.50. The rest of the stake goes to the layers.
Does Orbit Exchange have horse racing?
Its menu has Horse Racing Betting and Today’s Card entries for horse racing, and its exchange rules carry rules for horse racing markets. Which races are open on a given day is read on the exchange; the menu entry by entry lists the rest.
Orbit Exchange opens through a broker, and four of them do it. The way into the exchange sets out the routes, and the exchange guide has the rest of the mechanics; the page on exchanges sets the field wider.