There has been some interesting results following Open Class races in Melbourne on Saturdays only.

The only other rule is the qualifying horses must be between $2 and $4 inclusive in the morning paper (I use the Herald Sun)

These figures are from 5/08/2006 to 25/05/2013. (nearly 7 years)

Bets 682
Wins 222
Win S/R 32.6%
Win Bank +83.10 units
Win POT% 12.2%
Places 439
Place S/R 64.4%
Place Bank +20.74 units
Place POT% 3.0%

The longest losing run was 12 and the longest winning run was 6.

With some logic based elimination rules the following is achievable

Bets 186
Wins 85
Win S/R 85%
Win Bank +89.70 units
Win POT% 48.2%
Places 132
Place S/R 71.0%
Place Bank +26.10 units
Place POT% 14.0%

The longest losing run was 9 and the longest winning run was 5.

I put this up to show that if you concentrate on niche areas in the punting market profits are achievable over many years.