After viewing Shauns great thread (and the profit thereof )on the top 2 ratings I thought I give my own idea a go as a trial.
I will only do the later races as the return in most cases is better.
As 2 horses are given I want a Minimum $3 BUT no upper limit.

Tamworth
Race 5 H 2 + 10

Race 6 H 3 + 6

Race 7 H 4 + 7

Race 8 H 4 + 10