I have been testing some systems via RaceCensus data base of late and the 2 major bits of form that are always needed to make a profitable system are days since last run and price, i am finding that 7 days is a good mark but it does reduce the amount of bets and less than $8 or first 2 in betting.

Most of the better systems seam to only have between 100 and 200 bets a year, i did come up with a system that had a POT of 4% tab divis but i was looking for win systems and forgot to save the data i was searching for.