Out of interest, today at Mackay R6 had a field of 9 starters, and I layed every horse for the minimum $30 with S.P.

I expected to lose 5% commission whatever won because I thought an apportionate amount would be bet according to each's price for a set liability of $30, but when the S.P. prices were loaded only the fave showed a loss if it won the race. Fortunately it didn't.

Anyone knows how the amounts are calculated, and why only the fave (I presume) will show a loss?