I've been doing some grappling with a friend of mine. He is the same size as I am and his knowledge of submissions and positions is lesser than mine. Everytime I grapple, I am relaxed and I don't use 100% of my strenght, as oppose to him. I am able to submit him from the guard or side control or mount. But everytime we start on our knees, he somehow gets the hold of my head, whether I shoot low or from the side. It's either a guillotine choke or the bully head lock (see Carlos Newton vs Pat Miletich). None of them seem to hit my neck, more so the jaw. It hurts like a bitch. Sometimes I am able to overcome the pain, find a good position and break the lock. Most of the times I just tap, because I have a feeling he's going to break my jaw. I was wondering, if there is a simple defense or trick to overcome a lock like these two. It's not a choke, more like squeezing my head with everything he's got. I've never seen somebody tap to this (in MMA). Do I just have to overcome the pain everytime and then eat through a straw for the next couple of days. Does anybody have any advice? Thanks in advance.