Stugots, the higher price ranges on Betfair can easily be double, and sometimes treble that of the TAB, as I often noticed when I used to lay outsiders for a couple of months.

So a 22% Betfair net advantage over the TAB in the $5 to $20 price range is surprising.

Because your results come from a relatively extensive period of three months, one could easily assume that selecting every horse in the $5 to $20 TAB price range, by betting them on Betfair would produce a profit of a few percentage points.

As a matter of interest, I used to back at level stakes every horse in the Betfair price range of $7 to $20 and showed a profit over a short period of time. I seem to think I did this with fields of 11 or more, but I can't be certain. So if a winner paid more than $20 I most likely missed it. However, I've seen horses under $20 in the TAB market that paid at least $40 on Betfair. I might have a look at TAB $5 to $20 price range.