This video technique post is by 3rd-degree Roger Gracie Jiu-Jitsu Black Belt Nicolas Gregoriades.
Jiu Jitsu's Most Basic Submission
The arm-lock from closed guard was one of the first moves I ever learned. Just when I think I have it mastered, somebody comes along and teaches me a couple of little details that refine and improve it. Once you have mastered 'first-phase' attacks in BJJ, you can start adding in second and third phase attacks for use when sophisticated opponents counter you.
Dealing With Your Opponent's Defence
This video shows a three-phase sequence. It takes you from the initial attack into a response to a common counter, and finally shows a powerful method for finishing the submission when the opponent defends in the tricky 'spider-web' position.
Drillers are Killers
Although this is a complex sequence, it is composed of techniques that are high percentage and for which opportunities will often be presented. It might take a while to drill it until you can both remember it and pull it off against a resisting opponent, but the rewards will be well worth it.