I've looked at this for a while and it seems to go quite well. Each horse is backed with the field so there's a possibility of getting the quinella once or twice (or, of course, not at all).

TRENTHAM
RACE 6 (Thorndon Mile)
5 6 7 11 12 17 (all with field - cost for $1 = $96)

RACE 8 (Cup)
3 5 11 14 16 18 (all with field - cost for $1 = $102)

Amazing that with two groups providing television coverage of racing that one can't broadcast what is by far the best meeting in Australasia today.