Minimizing a punter’ backswing will maximize the height of the contact point (foot meeting ball). The higher the contact point, the higher the trajectory of a ball in flight (hang time).
To maximize hang time, punter’s must also be mindful of possessing the football until just before the plant foot settles to the ground. The longer the ball is possessed by the punter, the less time gravity affects the ball’s drop. Finally, the less time the ball drops the higher the contact point.