I have been playing around with a sytem with some promise, although being in the very early stages looks promising. i havnt been keeping records and havnt been punting them but it seems to throw up pretty consistent winners.
rules
1, 1200-2200 races only
2, no maidens, jumps, 2 yo's
3, must of won over distance, and been placed at track
4, must of ran 5th or better last 3 starts (no 12x3, must be 213 etc)
5, barrier 1-8, allowing to move in from scratchings
6, ran within 200m of last run, and within 15 days
7, no selection if going from provincial to city
8, carrying 56 kg or less
9, field sizes of 14 or less
10, no bet if won 2 in a row

Then i use my own judgement on the jockey, if its a spastic on, its no bet.
I have also been toying with the idea of adding a price restriction, or tipped by the pre post tipsters to eliminate the longer priced horses. would be interested to see if gelded horses perform better also.

cheers