I'm an EXTREMELY low-level grappler, my only pros being knowing a lot of holds and the ability to lock both feet behind my head simultaneously. I don't have any official training, but I'm a member of my college's BJJ club (more for fun than anything serious). While my favorite move is the gogoplata, my best is the heel hook (yes, I'm really careful about it). Recently, in situational practice where I started in full mount, I latched onto my opponent's foot in a scramble and tried to get in position, but he had his weight down and despite wriggling for about a minute and a half, I couldn't lock it under my armpit. He actually somehow ended up taking my back and choking me out while I still had his foot. How do I break someone down who's standing on the leg I'm attacking? Scissor the knee?