Lay betting on Betfair: liability, SP lays and fixed-stake lays explained

Last checked 13 October 2026

A lay bet is a bet that a horse won't win. You're the bookmaker: you take somebody's stake, and if the horse wins you pay them out at the odds. The amount you'd pay out is your liability, and it's the number that matters more than any other in lay betting.

The maths

Lay £10 at 4.0. If the horse loses, you keep the £10 stake (less commission). If it wins, you pay the backer £30: their £10 at odds of 4.0 returns £40, and £10 of that was theirs to begin with.

So liability = stake × (odds − 1). That's the whole formula. The stake is what you can win. The liability is what you can lose.

Before commission. Commission is charged on what you win on a market, not on your liability.

Read the last column twice. A lay system can be right 90% of the time and still lose money if the 10% it gets wrong are at big prices. That's why lay betting records need to be read differently from backing records, and why the price cap matters more than the strike rate.

Two ways to size a lay

There are two honest ways to decide how much goes on a lay, and they produce different-looking records from the same selections.

• Fixed stake. You lay every selection to the same stake, say £10. What you win is always £10. What you can lose moves with the price: £10 at evens, £190 at 20.0.
• Fixed liability. You risk the same amount every time, say £40. What you can lose is always £40. What you win moves with the price: £40 at evens, £10 at 5.0, about £2 at 20.0.

Here's why the choice matters when you're reading a record. Take 100 lays at a £10 stake, average price 5.0, 90 of them correct.

• 90 winning lays × £10 = £900 won
• 10 losing lays × £40 = £400 lost
• Profit £500

Quoted as return on stake, that's £500 on £1,000 staked: 50%. Quoted as return on liability, it's £500 on £4,000 risked: 12.5%. Both are true. Both describe the same bets. A lay tipster quoting the first number isn't lying, but you need to know which one you're looking at before you compare it with anything else, and before you work out what bank the system needs.

Laying at SP

When you lay at Betfair SP, Betfair asks for your liability, not a stake. The stake is worked out at the off from whatever the starting price turns out to be. A £20 liability at an SP of 5.0 is a £5 stake; the same £20 at 11.0 is a £2 stake. You can add a maximum price, and the bet is only struck if BSP comes out at that price or shorter.

What you can't do is lay at SP to a fixed stake. Betfair doesn't offer it, because the stake can't be known until the price is. So a system written as "lay to £10" has to take a price in the market close to the off, which is how the lay systems in xCloudBot are placed, while our win systems go on at BSP. There's more on what SP is and isn't good for in Betfair SP explained.

The setting that saves you: maximum odds

Every lay system should have a maximum price, and it should be set from the system's record, not from nerves. If the record was built on lays up to 8.0, a cap at 8.0 means your worst case on a £10 stake is £70, every time, and you know it before the day starts. Lift the cap to 20.0 "to get more bets on" and one winner at 18.0 costs you what seventeen correct lays earned.

The cap does two jobs. It limits liability, and it keeps you inside the range the record was built on. A lay system that was profitable at prices under 6.0 isn't the same system at 15.0; the horses are different, the reasons they lose are different, and the record says nothing about them.

What lay records look like, and why

Lay systems win often and lose big. A strike rate of 80% or 90% is normal for one that lays short-priced horses, and so is a losing run that takes back three weeks of profit in one afternoon. When you look at a lay record, look at the average price, the biggest price it ever laid, and the worst drawdown, before you look at the strike rate. Then read how to read a tipster's results for the rest of it.

Lay betting in xCloudBot

xCloudBot has 22 lay staking plans, including fixed stake, fixed liability and a plan you build yourself, and you pick one per system. Each system has its own minimum and maximum odds and its own stop at a profit, a loss, or a number of winning or losing bets for the day. Three lay systems come with the subscription: Andys Lays on every plan, the FormBreaker systems on every plan while they're in testing, and Betty Lays, an AI model that picks horses to lay, on Premium. Betty Lays and Andys Lays are on the public record at PuntHub, every bet including the losers. If you'd rather watch one on paper before risking liability, run it in simulation mode first.

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