An interesting comment on another thread whether a system can be profitable with mechanical rules only. After reading some forums getting a basic understanding of some statistics I have been manually testing the below theory with small POT on level stakes.

The rules are:
100 or 99 raters Unitab only (approx. 37% winners)
First 3 in prepost only after scratchings (racingnpost)
Max 2 horses per race.

Level stakes.

Gives a punter a quite few bets with steady stream of winners. As I've been doing this for a few weeks manually there isn't alot of data to confirm but it is showing positve POT at the moment after approx 300 bets. I've been testing everyday for interest.

Cheers