Two points of control is always than one: The of Jiu jitsu is always about control. If you can nail down one significant part of your 's , that will certainly be a great step towards control. It is always better however, to nail down two major parts of the body so that between the two, your opponent cannot begin to extricate himself from one because of the control from the other. Each element of control protects the other from a escape. Here, my legs control my training while the on the arm controls arm and shoulder, making escape significantly more difficult than if just one of the these control points was being used