Hi Michal,

The SP prices can sometimes be a bit random, however they're usually pretty reliable. It's an intricate calculation based on the prices requested for bets and lays on each particular horse before the race.

There is a function with Betfair SP, where you can set minimum acceptable price, which will stop you from getting burned. I really like this function as you can put your bets on in the morning, go to work and not worry that you'll have to take whatever price is on offer, as you would if betting with the TAB.

I only bet in $5-20 units so couldn't tell you about betting in larger amounts.

Hope this is of assistance and if you have any questions at all, give me a holler.

The Schmile