Originally Posted by
Erwann
Hey Ryan - my answer here will sound a lot like my previous one to Griffin - if your opponent can turn on his side you are not as tight as you could be, and the hold isn't properly cinched. When I grab that neck, my opponent is locked in place. I am squeezing inwards & downwards. My hips are heavy the whole time. The only way for my opponent to get to his/her side is to slide his/her opposite arm across their chest - thereby giving me their back. Even that shouldn't happen unless I alleviate pressure or loosen my grip during the roll. The crank is far less effective if on their side since you don't have the mat helping you lock them in place. If on their side, they can scoot away, further loosening your grip.
Basically - if the grip is loose at the beginning (ie: you rush into the roll and don't adjust it) it'll be exponentially looser during and after the roll, giving them the opportunity to get on their side. Make sure it's cinched (and you control a leg) BEFORE going for the sweep.