Haha it's a submission hold in BJJ, there might be another name for it, but that's what they call it at the dojo I go to. It's a hold you can go to if someone has mounted you, you use their own arm to choke them, then flip them over so you are in mount. You have to be able to sweep your bottom leg out fast though so you don't land on it... and... I kinda wasn't fast enough that time