Over the past 3 days if the following system had been bet:

1) 6 to 10 runners.
2) All runners with a minimum of 3 career starts.
3) Identify all under $20 in Don Scott's market.
4) The (under $20) selections must not exceed half of the field.

So if there are 4 selections the field must not be less than 8 runners.

Over the three days there were 14 winners from 17 qualifying races which comprised of 54 selections.

Betting with Unitab divvies the return was $55.80 for a profit of $1.80 or a POT of 2%.

Betting with Betfair S.P. the return was $59.19 (includes their takeout) for a profit of $5.19 or a POT of 9%.

I have looked at this system on-and-off whenever the interest held me and it wasn't unusual to strike a double-figure winner, even with Unitab.

If anyone's interested, today's selections are:

Rocky
1/3, 5, 8
3/3, 4, 5, 7
4/1, 3, 5
5/1, 5, 7, 8

Hawkesbury
2/3, 8
7/1, 5, 7

Pinjarra
1/5
7/1, 2, 3

There are 23 selections.