An overhand punch is a semicircle movement thrown with the rear hand. It can also be a vertical hit. In most cases, it is applied whenever there is a bobbing or slipping movement on the opponent's part. You can get around your opponent's guard by throwing overhand rights. With the use of body weight as a starting point for the drop, a lot of power can be delivered when using this technique. It is a valuable technique for any martial arts. Check the tutorial here.