Here are 3 variations of hitting an armbar from the mount. They all hinge on getting a good cross collar grip, transitioning to the S mount, and finally finishing based on what your opponent is doing with their arms. One critical detail to remember through all of these is that it’s not all about the arm you are attacking. What you are doing with your other hand (preventing an escape) is equally important.

(Starting Position)
Start Mounted with a cross collar grip with your left hand.

(Set-up)
1. Lean over to your right (over your opponents left shoulder). Use your chest and head to to fold your opponents left arm over their face. As you do this slide your right knee forward behind your opponents head.
2. Continue applying pressure with your chest on top of your opponents arms and face as you kick your left heel up under their armpit and establish the S mount.

(Basic Finish)
3. Reach through your opponents arms with your right arm, trapping their near arm, the left arm, and grab your own collar.
4.With your left hand, grab their near leg knee (gi) as your rock down towards their knees and then finally arch your back to finish. Remember to keep your pant-leg grip throughout.
**if they are locking their arms, put your bottom leg heel inside their far elbow and push out. this will brake the grip.

(Alternate Finish – they are keeping their elbows very tight)
4. Reach behind their far elbow and pull it up towards you as you rock forward towards their head as your arch your back to finish. (This is kind of like an Americana arm crank).

(Alternate Finish – they are grabbing their own elbows and your can’t get your arm laced in between theirs and trap their right arm. so, attack the other arm from the other side)
4. With your right arm, reach under their right forearm and grab the top of their right tricep.
5. Lean across their body and post on your left arm as you switch sides, placing your hips under their right arm. Lean back fast for a quick submission.