When you throw a punch, you will create some opening. Your opponent will punch through that opening, In the following clip, A throws a left hook. B uses a right hook to punch through the opening that A has just created. If A can change his left hook into a back fist as shown in the following clip, A can close the opening that he has just created. B's right hook will be blocked by A's left back fist. It's always a good idea to "close the opening that you have just created" when you miss your punch. In order to do that, you have to think ahead. Your thought?