Heh, hammer lock.
My buddy Paul got into a fight with some big dude in a Topeka pool-hall. Paul's a medium-build guy... 5'10", 160#. Dude he was fighting was at least 6'4", 230+. Choke hold... big dude thrashed around a bit, but after a few seconds, dropped to his knees and tapped-out.
Doesn't matter how big/bad you are - if you can't breathe, you can't win.