The loop choke is one of the most deceptive submissions in BJJ. It doesn't look threatening until it's already on. As the instructor puts it: "For most people, if they don't know the choke, it looks pretty innocuous. It doesn't look scary at all. He doesn't feel threatened, but it can come on fast."
Here's how to set it up.
Start with a cross-collar grip, but grab LOWER than you would for a cross choke. You want about one to three inches away from the neck. This grip would never work as a cross choke, but it's the ideal depth for a loop choke.
Keep that gripping arm stiff. You're controlling distance here -- you don't want your opponent collapsing on you or coming forward on his terms.
The key mechanic is where your thumb knuckle ends up. When you wrap the loop, you want your thumb knuckle on the bottom of the trachea. The finished choke is half gi, half forearm and thumb bone across the neck. That's the sweet spot.
For the footwork: your hand goes to the ground, then spin your foot behind you. Come up, cup the back of his head, pull it down, and get your elbow HIGH. Most people leave the elbow too low -- that kills the choke. The hand you pulled down with shoots through underneath, deep.
The loop choke is especially dangerous when your opponent passes your guard. If he shuffles around to the wrong side, he puts himself right into it.
For more submissions from the gi, check out our complete BJJ submissions guide. Get the full course in Scott Sullivan's BJJ 101 System.