OL and anyone else laying on betfair,
laying to win a certain amount is the wrong way to do it. You should have a total lay risk amount(say $100/$200, a % of your bank, whatever) and lay to that figure whether your laying a 2's on shot or a 20/1 shot.
I agree.
For those interested I have attached a worksheet that calculates the optimal amount of your bank to risk and the stake required from the bettor for you to have that risk, based on:
i) The price you lay the horse
ii) What the horses true price should be (ie it's true prob of winning n a 100% market)
iii) Your Betfair commission
iv) Bank size
The calculation is the 'Kelly' figure.
With all horse betting, as true probabilities are not precisely calculable, it is probably best to use a proportion of the Kelly figure. e.g. 50%
Another way is to assume a standard conservative edge across all your lays and risk the same percentage on each bet.
I do the latter and risk around 12% of my bank with each lay.
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