One move – many variations: When we begin Jiu jitsu we talk about a given in the singular – we talk about an “arm bar.” As you develop you come to realize there are other variations of the arm bar – they are still insofar as they share the same basic mechanics – but the applications and positioning are quite different. All the major moves of Jiu jitsu have this feature and it is crucial for your development that you understand each of the variations and how they relate to each other. This is a BIG part of what expertise in the sport means. As the of your opponents increases you will be required to show ever increasing knowledge of the nuances of variations and switching between them in order to defeat determined and skillful resistance. Here, applies one his favorite arm bar variations that does not have a crossface leg at all. This would seem to be a weakness, but the control over the near shoulder makes direct head control unnecessary. Note that he has to switch the breaking fulcrum from right hip to left hip to get optimal breaking pressure with this variation. This kind of nuanced understanding of the variations is what you will require the further into the sport you go.