Denny Prokopos is the head instructor at 10th Planet Jiu Jitsu in San Francisco and Eddie Bravo s first student to be awarded a black belt in 10th Planet Jiu Jitsu. Check out Denny s pretzel grip guillotine filmed during a seminar at 10th Planet Jiu Jitsu London. Visit for details on how to pick up our magazine in print and digital. Follow us on Facebook: Follow us on