Betfair SP value

[pinkisntwell]

Let's take a look at a typical horse racing screen a few moments before the off: Assuming that the exchange prices are very efficient (as they normally are in betfair), isn't there some value of backing the SP whenever it's projected to be over the exchange price and laying it whenever it's below? Am I missing something here? I know these are projections and are bound to be different than the real prices one will get, but surely they'll be close enough. It can't be this easy, someone bring me back to order.

[Datapunter]

Re: Betfair SP value Aren't you making a timing error. You say use the SP as a marker and back if the available price is above. But your assumption of the SP being a valid market is based on a completed SP at the OFF, you would be placing a bet before that. Otherwise where would you get the time to place the completing Lay bet. So the SP when placing the bet perceived to have value is not the same one at the OFF which is what your are basing this on. You have no way of knowing how the prices and therefore SP will evolve over time. It is quite possible that you see an SP of 4.00 with an available price of 4.2 only to then see both the price and SP rise to 5.00 Easily paper traded for a while.