Just spent around an hour going through all the wins since this plan started back in November replacing the prices I won at with Betfair SP, to see if it would be profitable to back these selections at Betfair SP.
Obviously the aim of my plan is to back horses which are the subject of market moves, at an artificially high price, to hopefully beat the industry SP and therefore lock in an edge. With this in mind, it would perhaps not be surprising if just backing at SP heralded no profit whatsoever, or even left us with a loss.
Interestingly, backing at betfair SP HAS made a profit - of 38.12pts (assuming a betfair charge of 5% on successful wins). If you had a betfair charge of 2.5%, the bank would be sitting on 52.20 pts in profit.
Comparing this to my actual level stakes profit of 158.64pts, it's obviously not that impressive. But it's still interestig to show that backing horses at Betfair SP which have been the subject of (in some cases) significant market moves, then you can still make money (at least from my current sample of nearly 600 bets).
However, the important conclusion is that the horses I am selecting are, in a vast majority of cases, being backed at better prices than they go off at at post time, and that is what it's all about.