Is the way you punch to the body say the liver the same way you punch to the chin/brain?

I mean they are two very different targets the brain incases in a small light shallow but hard very "mobile" skull. The liver incased deep in a big soft "unmobile" body. The brain seems to shut down from shock or a rapid violent acceleration and deceleration. The liver seems to give you a tonne of pain if you kinda stab it with your fist and arm.

There seems to be boxers that are good body shot KO artists and they often make lousy head shot artist, and there are good head shot KO artists that make lousy body shot KO artists. The body shot KO artist tend to be strong (think ricky hatton) and the head shot KO artists tend to be fast (think pacman)

I was thinking teh fast guys can cause that shock to the brain the rapid acceleration and deceleration, and strong guys can better dig or stab their arm into the liver or break the ribs.

But thats just my theory.

My question is is their an optimal way to punch to the head and an optimal way to punch to the body? Or should all punches be fired in the same way regardless of what target/body part you strike to?

Obviously tehre are different body shot techniques to head shot techniques but I mean should the contact time apon impact, snappiness of the punch, how much you drive through etc etc change depending on whether you go to the head or body?