Marcelo Garcia teaches his guillotine from closed guard. He prefers to use this version of the guillotine when the opponent’s posture isn’t too high. In the video, the opponent inside the closed guard is connecting his elbow to his knee. Marcelo Garcia then starts to reach across, while using the other hand to post to increase the reach of his arm that is going to wrap around the opponent’s neck.
As he wraps around the neck, Marcelo’s detail of his guillotine from closed guard is to remove all the space by attaching the forearm to the neck, while the other side of the neck is in contact with the rib. In a live sparring scenario, Marcelo mentioned that the movement of wrapping the arm towards the neck is like a punching motion since you’ll most likely not have the time to wiggle your arm to make the guillotine tight.
Once the arms are tightly wrapped around the neck, he then removes the posting hand and fall on his back. The hand that was posting then holds the hand that wrist of the hand that is wrapped around the neck. His choking hand’s position needs to be in thumbs up position in order for the hand’s blade to hit the throat.
And to finish the guillotine, Marcelo Garcia then raises the elbow of the hand that is connected to the choking arm. And what he does is even try to connect his elbow on top of the guy’s shoulder in order to add more leverage to the choke and possibly control the posture of the person inside the closed guard.