Marcelo teaches another instantiation of the Guillotine Choke: If your opponent is reacting defensively while held underneath your Side-Control, i.e. they're keeping their elbows tucked in closely, you have an opportunity to reposition their posture into a more favorable angle for attack. Begin rolling your opponent's chest towards you without giving up too much space in between; if you notice their chin untucked, punch your arm around their head while landing your ribcage against their neck. Lean backwards slightly to make room for your hands to connect together as a Ball-n-Socket Grip, i.e. your choking hand remains closed as a fist while your opposite hand supports it by cupping over your knuckles. Focus your bodyweight onto your opponent's neck by directing your squeeze through your ribs and elbow so that there is bilateral pressure.