Matt Thornton, CEO of SBG International & Head Coach at the world renown SBGi PDX Global Headquarters in Portland, Oregon applies the Skinny X concept here to sweeps when the opponent stacks in the guard. Some vital points here on keeping your neck safe, irrespective of whether you believe you have a triangle or armlock that is close, give it up rather than get stacked on your neck. Note the way Matt flexes his feet in what is called dorsal flexion to maintain connection and structure to his opponent as well as the way he uses his body to change the angle of his hips and feet. The underhook also reaches up to the Skinny-X. Another application of the Skinny X is often shown here by John Danaher where he rotates under into the skinny X angle of one of your opponent’s legs.