A Fight Broke Out Part 4: Know When to Clench! What is clenching? To clench means to grab hold of something as you gather your strength. It is also a strategy used to reposition yourself. In boxing, it is used to help the person catch their second wind and reposition themselves as well as their opponent. Today, Coach A will talk to you about the strategy of knowing when to clench. This is most vital because at this point you may have been in a fight about 8-9 rounds now and you are getting tired of fighting but you know you can't call the fight just yet. So don't throw in the towel just yet. CLENCH!