Hi Bhagwan

I too am not sure what you are after but the lay price is the opposite or inverse of the back price.

If a horse can be backed at 5/1 to win then backing it to lose would be 1/5

Because they will be priced in decimal the 5/1 will be 6.0
To get the decimal lay price you have to take 1 fom the 6 leaving 5
Divide the 1 by 5 =.2
Add the 1 back = 1.2

On Betfair placing $2 in the backers stake box give a liability of $10. In effect the $10 is your stake and the $2 is what you win so the odds are 4/10.

4/10 = .2 but because decimal prices include the stake 1 must be added back to get the 1.2

Now I'm confused