If your original system has a 10% POt and you add another 5 rules, does that mean the your system will drop below the 10% POT. You have have to say no in theory.

I using a 2 step model. Using 3 rules as a base to get a 10-15% POT and adding extra filters.

I know in the end of the day, the horses that should have won only to be let down by the jockey or sweating/playing up at the barriers.