What makes a strategy work?

Application

Strategies that apply only in some areas don't work.
Strategies that apply everywhere, do.

Simplicity

Strategies that are too complex for people to carry around in their heads can't possibly work.
Strategies that are simple enough for people to carry around in their heads, can.

In other words, to ensure that a strategy actually works, it has to (a) be simple and (b) apply everywhere.

We call simple strategies that apply everywhere, systemic strategies (systemic means common to the entire situation - click here for an overview).

Simple everywhere