How many of you have all truly played football? I mean up to like the college level? The fact is, when you're going all out, trying to make a play, trying to rope down a slippery quick player, who if he gets his feet under him again, is gone in a flash, who is trying to leap over the middle and make that catch, WHATEVER, that situation might be????? You aren're premeditating exactly how you're gonna bring the guy down, stop him, or delay him....YOU JUST FREAKING DO IT! It's instinctual.
All these leading with the helmet laws, hitting a defenseless receiver, touching the QB below the knees, or anywhere in the head, etc etc etc are all BS, and luck of the draw. You're still gonna have those hits every game, no matter how intense you make the penalty, because at the end of the day, football is still an instinctual sport.