Here is a choke from a NO arm in triangle choke that is fantastically tight! The liberty choke is another variation of this (see video) using the arm in a mission control posture. I was shown this by a Pedro Sauer student as he had said he had got trapped in this a few times and had to tap from it. At first glance, I didn't think the move had merit and would be easy to escape if applied. I was surprised on how tight it actually was.
