Another look at the Key Lock or Americana but this time from Side Control. Like the last time that I showed this technique the setup is not important (although this setup is much better than the setup from the mounted instructional). The important thing about this technique is that you get the elbow to the hip.
Make sure that when you do this you practice it slowly so that you can get a good feel for your opponents comfort zone. Often times if you bring your elbow to their hip they will immediately tap. If you have done this variation from mount and thought it was tight it is easily twice as tight from Side Control.
When doing this move from Side Control it takes good control of your hips and your opponents base. DO NOT let your center line remain over your opponents. Often it will be unavoidable to initially cross to get the grip but notice how I immediately reverse and get as much of my base back to the correct side of the body.