3 CLOSED GUARD: Cross Collar Choke to Armbar to Criss Cross Armbar with Professor Greg Walker June 28, 2016 by Gary Berger Leave a Comment 0:40 Cross Collar Choke / 1:15 Armbar / 2:23 Criss Cross Armbar Professor Greg Walker is a Brazilian Jiu Jitsu Black Belt under Gustavo Machado and teaches at the UFC Gym Norfolk, VA. 457 5