Another idea:

Two selections per race.

1. Find the runner with the highest QTAB rating among those TAB numbers lower than the number of the favourite. Bet $4 to win.
2. Find the runner with the highest QTAB rating among those TAB numbers higher than the number of the favourite. Bet $3 to win.
3. Where the fave is #1 take the two highest QTAB ratings in the field (but not the favourite). $4 on the lower TAB number, $3 on the higher.

Only tested this over 60 races but it pays good POT in that sample.

Lots of uses for the QTAB ratings, and they're free.

Hermes