Back control
Rear naked choke
The highest-percentage finish in jiu-jitsu. From the back, your arm wraps the neck from both sides, and once it's locked the escape is mostly gone.
Step by step
Secure the back
Get both hooks in and a seatbelt grip: one arm over their shoulder, one under their arm.
Slide the choking arm under the chin
Feed your top arm under their chin until the crook of your elbow is under their throat.
Lock your bicep
Grab your other bicep with the choking hand. Put your free hand behind their head.
Squeeze
Tuck your head next to theirs, pull your elbows together and expand your chest. Give them time to tap.