Artemis BJJ (MYGYM Bristol), Can Sönmez, Bristol, UK - 07/12/2016
From half guard, get in as low as possible, curling in towards their leg like you do for the toe grab sweep. Sometimes they keep their foot out of range, which is when I like to try for a position called deep half guard. Shoot your non-underhook hand between their legs, reaching for their opposite bum cheek. Try and get a shallow underhook too, in order to assist with pulling them off balance. The key thing here is to get your shoulder underneath, rather than trying to wrap their leg with your arm. You want to wriggle underneath as you swivel onto your back, your head on their thigh. You can also push back with your head and neck, to make it tougher for them to step their leg over.
At the same time, drag their leg towards you, using the leg you have on top. Your aim is to get your entire body underneath their leg, accomplished by your swivelling motion. You may need to push off their hip with your other hand, to help that wriggle underneath them. Once you've swivelled, reach your first hand around the outside of their leg, gripping the inside of their knee. You other hand tucks underneath their leg, so they can't grab it.
Finally, your legs are trapping their one leg. Make sure at least one of your legs is hooked over the top, so they can't just remove their leg and pass. Your other leg could be locking your other, or some people prefer to hook under their opponent's leg, meaning they can lift.
For the outer roll sweep, commonly known as a Homer sweep, walk your legs towards their other leg. This is where it gets the name, due to that scene from The Simpsons where Homer is on his side, running in a circle on the floor. You're doing the same motion (bonus points for 'woot woot woot' sound effects ;D), trying to cut the angle. Once that angle is acute, spin the other way. Continue to hug their leg tightly. They may attempt to triangle, so don't leave any space. You can then either drive your head to the far hip to pass their leg, or alternatively, reach your arm to their far hip and pass the other way.
Teaching Notes: I added the technical mount escape entry as a drill, hopefully helping people get used to deep half. One of the problems I keep forgetting when teaching more complex techniques like this is that the person on top may not react as you'd expect. A number of people were leaning way forward, in which case you'd try and pop out the back. I guess I could teach that as a technique too at some point, but it is based around a mistake.
Next time I'll continue to emphasise getting the shoulder all the way under, as well as keeping your back down so they can't try crawling onto it. Though the more I teach deep half, the more I think it's better suited to the intermediate class rather than all levels. It probably requires some prerequisites to work as a class.