Head control: There is a reason why they classify us as vertebrates – our spines are the center of our body. On top of that spine is our head. The spine is the longest lever in the human body. The head is at the end of that lever. If you control the head you can exert tremendous leverage that can be used to control the whole body. Look for opportunities to control the head – many are pretty obvious but some are more subtle. Understand that you can exert pressure on the head in both linear (eg snap down) and circular (eg crossface) directions – be sure to use both. Understanding Jiu jitsu is to a large degree, understanding the human body and its essential nature. Our spines largely define our physical lives – make sure your Jiu jitsu reflects this fundamental fact
