Agree totally. I have been developing my own system over the past 6-12 months. I have race screening criteria:
1. only bet in fields between 8 and 10 runners
2. Must have exposed form (greater than 2 runs this prep) which generally means 1400m+.
3. Never bet on 2yo, or jumps.
This narrows my race betting options down to one or two each Saturday. I then apply a rating system which takes into account track and distance form, hoop, strike rate, weight, ave prizemoney, barrier, runs this campaign.......
I produce a rating which I convert to a percentage. If the delta between the first and second rated horse is 10% or more then that is my selection. At the moment I am averaging one bet every week. Last Saturday it was Self Interest which ran third and paid $1.60. I have only been keeping records for the past 3 months, but in that time have had 11 bets for 10 collects. I wouldn't say I have 'cracked it' but I am going ok. Now need to refine my staking plan so any help here would be great.