How To Do Brazilian Jiu Jitsu: Clock choke

This Brazilian Jiu Jitsu technique is illustrated by Mauricio Gomes and his son Roger Gracie.

1. Opponent is on his knees, ensure your weight is concentrated on the center of his back to prevent him from rolling. 
2. Open the lapel on the opposite side of your opponent from beneath his armpit, put your other arm across his neck and grip deep into his collar.
3. With the opposite arm (underneath his armpit) now grab the opposite collar.
4. Bring your weight forward onto your opponent's shoulders (to force his head down), and start to walk your legs forward.
5. Finalize your opponent by throwing your leg forward (changing your base) and pulling on his collars in order to apply the choke.