Why do you pivot your rear foot instead of just drive it forward for more power on a straight punch?

Question

Why do you pivot your rear foot instead of just drive it forward for more power on a straight punch?

Answer 1

You generate far greater power when you use whole body than when you throw a punch as you have suggested.

Without giving you more information than you need, I would suggest a simple experiment.  Get a friend of yours to hit you.  First hit, is thrown while pivoting on the rear foor, which turns the waist then the shoulder.  Have this hit thrown to your chest.  Then have him throw another, lunging as you would suggest and get back to me as to which hurts more.  

Also, pivoting on the rear foot is easy to maintain balance.  Lunge, and see how well balanced you are.

Answer 2

when you pivot you use your whole body in a motion that generates the force of the power. if you drive it forward you can risk losing your footing which can leave you in a bad position. and if the opponent knows that he can just move to the side, tap your arm to make you go forward more (in which it will be hard to recover) then hook you or throw any kind of good punch to the face or body.

Answer 3

im saying this from a MMA point of view when u pivot ur foot ur also using ur hips and legs to throw the punch so ur whole body is involved in the movement. but if you use too much u leave urself wide open to their counterstrike.