As far as my understanding goes. A standard protection bet would be w/ a hand such as 93s IP on a flop of 348. I.E. a weak made hand but one that is very vulnerable equity-wise against their non made hand range. For example K7o still has 6 outs and by not betting you would allow him free cards to realize his equity.

My question is therefore this, when you bet, it isn't really a hand which folds out better and there isn't a lot of worse hands that call so how important is 'protecting' your hand versus the fact your hand doesn't really gain value by betting?

Is there some math behind this, if so could somebody please explain?