Expanded the criteria a bit & came up with this for the last 18 months or so -

Races 2100 &>
Last Start Winner - if more than one in field selection is shortest SP
Field Size - any
All states except SA & TAS
Filters
- exclude all rising 4.5kg or more - (nice win system there if you like 1 bet a month)
- exclude all 3yo fillies - Oaks & the like
- maximum SP $20 (there were no winners over $20 but as a layer I just don't go there)

Selections - 399
Return less 5% comm $562
POT 41%
Winner s/r 14.3%

Not too shabby, someone with a more exhaustive db might want to chip in as I did record a couple of bad losing periods within the 18 months.