I know you have to hit the jaw near the nerves system but do you have to hit it hard like really hard

It takes only a few hundred pounds of force to knock someone out with either one punch to the temple or the jaw.

You have to have some power at least to KO sum1 in one punch

Back of the head

You'll never be a good fighter thinking that way, trust me.

I know you have to hit the jaw near the nerves system but do you have to hit it hard like really hard