Sorry for the delay in replying I have been off line.
The system, as I apply it, and I have changed some of the rules, is viable. For the past five months I have attained a P.O.T. of 14+%
I don't have the rules set out in a form which I can pass on as there is a Price assessment Chart which is to time consuming, to say the least, to type out.
But basically the system is based on the Zip Form Ratings in Sportsman and was designed, by a reader of PPM, as a rating and pricing method of assessment.
Initial Rules
Check Zip Form rating figures. If more than five horses are rated within two rating points of the top rated horse pass up the race.
Rating Adjustments
(a) add half a point to any horse with (c) or (td). Note Course OR Track and Distance.
(b) half a point (b). Beaten fav last start.
(c) half a point for top Jockey. (Your choice)
(d) One point for claiming apprentice where claim is permited regardless of size of claim.
Deduct
Half a point, after considering scratching, for any horse starting from barrier 15 or higher exept in straight course races Flemington & Victoria Park)
Final Elimination
If more than seven horses within 3.5 points of reassessed horses pass up the race.
Pricing Method
List all horses within 4.5 points from Top Rated Horse (eg. from 57 to 52.5)
Convert the rating margins to pricing
Top Rated Horse is now rated at 80
.5 behind 72
1.0 " 64
1.5 " 54
2.0 " 46
2.5 " 40
3.0 " 32
3.5 " 26
4.0 " 20
4.5 " 16

Now add up all the points of the rated chances and apply to the Prcie Assessment Sheet. PPM may send you a photostat copy of the sheet if you subscribe, they did for me but that was some years ago.
The actual percentage of each race should approximate 100% giving a 'true price' for the race.
OK so without the Price Assessment Chart the above is not worth a crock! But you did ask.