Thanks for your explanation, i asked this because the point is the nervous system and the will of the dog to bite... And where bite.

There are lots of mastiff show dogs that have a more power bite but faced with a game dog they lost and they are not able to bite well a smart pitbull that avoid the bite and attacks the mastiff defenseless point...

So if we see the hard mouth Lines like Eli and Bullyson they have a narrow skull in comparison to Mayday and redboy dogs
But they have a great mouth... In percentage more than Other lines... Sure we can find hardmouthed redboy, but not as frequentely as Eli or bullyson.

I think it the nervous system and fast twich fibers play the big role...