Liability in betting is the amount you stand to lose on a lay bet if the selection you laid goes on to win. It equals the lay stake multiplied by (the lay odds minus 1), so laying a runner for $40 at $3.50 puts 40 x 2.50 = $100 at risk to win $40 (an illustrative price).
Because the price multiplies the stake, liability can be many times what a lay can win, which makes it the first number to check before any lay.
How lay liability is worked out
When you lay, you take the bookmaker's side of someone else's bet. The lay stake is the backer's stake you accept, and it is what you win if the selection loses. The liability is the backer's profit, which you pay if it wins:
liability = lay stake x (lay odds - 1)
Turned around, for a liability you can carry:
lay stake = liability / (lay odds - 1)
Example: illustrative prices, not a real race. You lay Runner 6 for $40 at $3.50. Liability = 40 x (3.50 - 1) = 40 x 2.5 = $100. If Runner 6 loses, you keep the backer's $40 less commission: at an illustrative 6% rate that is 40 x 0.06 = $2.40, leaving $37.60. If Runner 6 wins, the backer collects $140 (their $40 back plus $100 profit), and the $100 comes from you.
Liability at different lay prices
With illustrative prices, what a $40 lay stake risks and the lay a $100 liability allows:
| Lay odds | Liability on a $40 lay stake | Lay stake for a $100 liability |
|---|---|---|
| $1.80 | $32 | $125 |
| $2.50 | $60 | $66.67 |
| $3.50 | $100 | $40 |
| $6.00 | $200 | $20 |
| $11.00 | $400 | $10 |
| $26.00 | $1,000 | $4 |
Below $2.00 the liability is smaller than the stake, at $2.00 the two are equal, and above it the gap widens quickly. Laying a $26.00 chance to win $40 means carrying $1,000 for a result the price says happens about one time in 26 (1 / 26 = 3.8%).
Liability on Betfair and other exchanges
On Betfair and other exchanges, a lay generally only goes on if your account can cover the liability. Once matched, the liability is held out of the balance you can bet with until the market settles, and funds are usually set aside for an unmatched lay too, because it could be matched at any moment. Each exchange's own terms set how it holds funds, so check them.
Only the matched part is a bet. If $25 of a $40 lay at $3.50 is matched, the liability on the bet is 25 x 2.5 = $62.50. What happens to the other $15 at the jump is covered in how to lay a bet.
Bookmaker names are trade marks of their owners. B337 is not affiliated with them.
Liability vs exposure
Liability belongs to one lay bet. Exposure is the most you can lose across every bet you hold in one market, backs included, once they are netted. With illustrative amounts, lay one runner with $100 of liability and back another in the same race for $15, and your exposure is 100 + 15 = $115: the result where the laid runner wins costs you both bets.
A back on the runner you laid does the opposite and can pull the worst case below the liability, as the exposure entry shows on a full market.
Common lay mistakes, costed
Each is costed with illustrative prices:
- Typing the liability into the stake box. Most exchange slips ask for the backer's stake. Meaning to risk $40 at $3.50 (a lay stake of 40 / 2.5 = $16) but entering $40 as the stake makes the liability $100, two and a half times the plan.
- Laying long prices to win small amounts. A $26.00 lay to win $10 carries 10 x 25 = $250 of liability.
- Forgetting that commission only comes off the win. At the illustrative 6% rate the $40 becomes $37.60, while a $100 loss stays $100.
- Chasing a lengthening price. Laying $40 at $4.50 after missing $3.50 raises the liability from $100 to 40 x 3.5 = $140.
Checking a lay before you place it
The lay bet calculator works out the liability, the lay stake for a liability you choose and the win after commission, and the lay betting guide covers where laying fits beside backing.
B337 places no bets on the exchange, so any lay is yours to place in your own exchange account. The Terminal shows Betfair back and lay prices beside 40+ bookmakers, so the lay price is in view before you decide. A free account opens a limited view of the Terminal with live odds, without the Betfair columns.
Risk: Betting involves risk. Laying a long price, like the $26.00 in the table, can put $1,000 at risk to win $40. A lay that is only part matched leaves you holding a different bet from the one you planned, and there is no guarantee of profit. See responsible gambling for limits and support.