I thought it would be comparing apples for apples because they are both determined at the time of the race starting (net of commission)?

I also hope its clear I don't plan on doing any arbing, I'm purely looking at the backing side of this.

Basically the test is, when a horse is <$4.00 top tote, top tote provides a higher return then betfair SP 64% of the time.

Ok lets move the price higher, when a horse is <$10.00 top tote, top tote provide a higher return then betfair SP 53% of the time.

Getting closer, continue testing. Now the figures above are all made up because I don't have the data. I'm just wondering if anyone has the data to be able to do that kind of test and find a rough guide for a cutoff point. Obviously it can only be a rough guide because prices firm or drift as CP said but say the cutoff is $15.00 and you know your horse is going to be paying $40-$50 then you know straight away I need to place this on betfair SP. vice versa if you know the horse is likely to start fave at <$4.00 odds then you know straight away ok I'm likely to get more value on top tote so i'll place it with a corporate.

Hope that all makes sense. Once again any help hugely appreciated and sorry for the posting in this thread CP. Can start a new thread if you wish?