If you add the extra rules to tighten up the selection process or to specifically isolate the value runners then I don't see a problem. If it's obvious that your selections are disadvantaged in certain states/conditions and your strike rate and POT increases as a result then go for it.

The see systems as a set of rules constructed to either:

(a) Isolate undervalued runners in the market
(b) Isolate absolute good things that have many lengths on the opposition and will be able to sit 3 wide and still bolt in. As most know, these systems usually end up with very low action.

Whatever you do, keep monitoring the results so that you can justify when things go good or bad and tighten things up if it's appropriate.

The Schmile

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The Schmile

"I buy when other people are selling.”
― J. Paul Getty