Hit and Run?

[TeamJagUS]

Ok I've got a question for all you baseball gurus out there. I know there's no hard and fast rule, but when and how often should the old hit and run be used, roughly? It seems that if it's used a lot (multiple times a game) that it becomes predictable therefore ineffective if almost every time a runner is on it's called (seems it would draw hard to hit pitches). Is this one of those things that gets overused by overzealous managers when they could instead let their better hitters be more selective about what pitch to hit or is there legitimate reason to run it without regard to situation? Appreciate any thoughts and discussion....