even greater power can be achieved if you start punch by turning your body in the opposite direction than the punch will land in the end. To make it more clear, f.e. you want to land a left hook; you turn your right foot, knee and hip like you would punch right cross, but instead you shift your weight back with turning the left foot, left knee, left hip and so on till you end your punch with left hook in opponent's face. That weight shift gives you additional force and moment and its a practically a k.o. punch if it lands on the opponent's jaw. Of course, its much slower then jab, or right cross without weight shifting on left leg, thats why boxers mask punches with other punches or simply with block, crouch or any body movement which will alert the opponent.