What is a lay bet?
Simply it is when you want to bet that a result won’t happen. So if you lay the draw on a football match it means you are betting the game won’t wnd in a draw.
What risks (liabilities do lay bets have)?
It is not as straight forward as with a normal bet. Normally you bet £10 and if the bet loses you lose this £10.
Lay bets are reliant on the odds. If the odds are 2/1 (or 3 in decimals) to lay the draw then if you stake £10 you will lose £20 if the game ends in a draw. If the game is not a draw you win your stake, so £10 in this case.
How are liabilities calculated? – You multiply your stake by the odds. So in the example above it is:
£10 x 2 = £20. (If you always use the decimal odds then it is (odds – 1) x stake. i.e. (3 – 1) x £10 = £20).
How to work out your stake.
If you only want to risk a certain amount on a single lay bet you need a way to figure out how much you must stake. For example you only want a liability of £10. If the odds are 3.35 (decimal) what should your stake be?
Use this formula: Liability / (odds-1) = Stake
So using the example above: £10 / (3.25 – 1) = Stake, therefore Stake = £4.36 (rounded up to the nearest penny). So a winning bet will make you £4.36 (minus a 5% Betfair commission).
Betfair does have an option to allow you to set you liability instead of a stake amount if you want to choose this.