Lay betting explained
What laying is, how it works on the Betfair Exchange, and exactly how liability is calculated — with the arithmetic worked through rather than waved at.
Lay betting is betting that something will not happen. Where a conventional bet backs a horse to win, a lay bet does the opposite: you accept someone else's bet on that horse, collect their stake if it loses, and pay them out if it wins. It is the position a bookmaker takes on every bet they accept, and a betting exchange lets ordinary punters take it too.
How does laying work on Betfair?
A betting exchange matches two users who want opposite sides of the same outcome. One wants to back a horse; the other is willing to lay it. The exchange pairs them, holds both sides until the race settles, and takes a commission on net winnings rather than building a margin into the odds. Betfair is the largest such exchange and the one most automation tools connect to.
When you lay, you specify the odds you are prepared to lay at and the stake you want to accept. That stake is the amount you win if the horse loses. If nobody wants to back at your price the bet sits unmatched and never comes into force; you only have a bet once somebody takes the other side.
What is liability, and how is it calculated?
Liability is the amount you lose if the horse you laid wins. It is the single most important number in lay betting, because it is always larger than the amount you stand to win. The formula is:
liability = lay stake × (lay odds − 1)
A worked example. Suppose you lay a horse at odds of 4.0 for a stake of £20.
- If the horse loses — which is the outcome you want — you win the backer's £20 stake. Betfair then takes commission on that profit, so you keep slightly less than £20.
- If the horse wins, you pay out at the odds you laid: 20 × (4.0 − 1) = £60. That is your liability, and it is set aside from your balance the moment the bet is matched.
So this single bet risks £60 to win £20. You would need to win three such bets to cover one loss, which is why lay systems typically show a high strike rate and why a high strike rate alone tells you very little. The number that matters is whether the wins outweigh the losses over a large sample — see ROI and strike rate in the glossary.
Liability rises steeply with odds. The same £20 stake laid at 2.0 risks £20; at 10.0 it risks £180. This is why most lay systems concentrate on short-priced runners: the liability per bet stays manageable.
Lay betting vs backing — what is the real difference?
Backing and laying are mirror images. A back bet risks a small stake to win a larger return; a lay bet risks a larger liability to win a smaller stake. A backer needs to be right occasionally at good odds; a layer needs to be right most of the time and cannot afford to be wrong at long prices.
The psychological difference matters more than people expect. Laying feels comfortable because most bets win, then one loss erases several wins at once. Backing feels uncomfortable because most bets lose, then one win recovers a long losing run. Neither approach is safer; they distribute the same risk differently across time.
There is one practical asymmetry. Laying requires an exchange account and enough balance to cover liability, so the capital needed to run a lay system is higher than the stake sizes suggest. A system staking 1 point per bet at average odds of 4.0 ties up roughly 3 points of liability per open bet.
Where do PuntHub's free lay selections come from?
PuntHub runs several automated selection systems and publishes them free every morning, usually by 8am UK time. FormBreaker Lays is a lay system; the others back. Every selection is written to the page before racing, and the results — winners and losers — are published the following day and kept permanently on a dated page.
That is the live example to look at rather than taking any of this on trust: today's free horse racing tips shows what was selected this morning and how yesterday's selections actually finished. PuntHub does not publish a projected return for these systems, and nothing on this site should be read as a promise of profit.
How is lay betting automated?
Betfair provides an API that lets software place bets directly into your own account. An automation tool reads a feed of selections, places the corresponding bets at the stakes you have configured, and reports back — without you needing to be at a screen when racing starts. This matters more for laying than for backing, because lay prices on short-priced runners move quickly in the minutes before the off.
PuntHub's sister product xCloudBot does this for PuntHub selections. Funds stay in your own Betfair account throughout: the software places bets, it never holds or moves your money. More detail is on automating your betting.
What should you be careful of?
Liability is the obvious one: a lay system can win nine bets in a row and give it all back on the tenth, so a bank that cannot absorb several consecutive losers is not big enough. Commission is the quieter one — the exchange takes a percentage of net winnings, which matters more for a high-strike-rate lay system than for a backing system with occasional big returns.
And no system, automated or otherwise, can guarantee a profit. Every service listed on PuntHub has had losing months and will have more; that is why every published record includes the sample size and the date range behind it. Never stake money you cannot afford to lose, and read the responsible gambling page before you start.
Common questions about lay betting
What is lay betting?
Lay betting is betting that something will not happen. Instead of backing a horse to win, you lay it — you take the other side of someone else's bet, so you win their stake if the horse loses and pay out if it wins. Laying is only possible on a betting exchange such as the Betfair Exchange, where users bet against each other rather than against a bookmaker.
What is liability in lay betting?
Liability is the amount you stand to lose if the selection you laid goes on to win. It is calculated as your lay stake multiplied by the lay odds minus one. Laying a horse at odds of 5.0 for £10 carries a liability of £40, because 10 × (5.0 − 1) = 40. The exchange sets this amount aside from your balance when the bet is matched, so you cannot lay more than your balance covers.
Is lay betting more profitable than backing?
Neither is inherently more profitable. Laying wins more often than backing, because most horses in most races lose, but each loss costs more than each win returns. Backing wins less often at bigger returns. Over enough bets, what decides the outcome is whether the odds taken were better than the true chance of the outcome, not whether the bet was a back or a lay.
Can lay bets be placed automatically?
Yes. Betfair offers an API that lets software place bets into your own account, and automation tools use it to place selections from a tip feed without you being at a screen. The funds stay in your Betfair account throughout — the software places bets, it does not hold money.
Where can I find free lay selections?
PuntHub publishes free lay selections every morning, usually by 8am UK time, along with the previous day's results in full including the losers. They are on the free horse racing tips page at punthub.co.uk/free-horse-racing-tips and each day keeps a permanent dated permalink.
This page is general information about how exchange betting works. It is not betting advice and not a recommendation to bet. 18+ · BeGambleAware.org