After 1 months betting , using LIVE bets , i have recorded 6 outcomes. Using the original system for win and place , using DD top place % as an alternate rule to p/m and a system using both rules combined. Results follow -

Prizemoney Rule -
Win - 12/48 (25%) Loss 12.2 units
Plac - 38/48 (79%) Profit 2.4 units

Place % Rule -
Win - 17/56 (30%) Loss 4.2 units
Plac - 38/56 (67%) Profit 3.8 Units

Both rules combined -
Win - 7/20 (35%) Profit 0.5 units
Plac - 15/20 (75%) Profit 3.8 units

Unflattering i know , but not a bad base set of rules to begin a system. think of the combo, backing place only and you end up with 19% in front. DD , combine with your filters (how are these going by the way?) and we might
improve somewhat. Will take it to 100 selections as advised and put up new results.