A MLB scout once told us that you have to have what he called a yes-yes-yes - no approach rather than a no-no-no-yes approach.
As I understood him, he meant that on each pitch you are looking to do damage as a default, holding up only when the pitch reveals itself as NOT hammerable.
A no-no-no-yes approach would I guess be the opposite, it's like "show me that you are hittable, pitch. But until you show me, I'm laying off." (although with a pitcher that cant find the strike zone....)
He says you should be poised to pull the trigger and have to make yourself lay off, rather than being poised to lay off and then having to make yourself pull the trigger.