[petke]

I'm no expert just an mma fan. The rear naked choke for instance. Once they get under your chin its hard to slip out. The bigger the chin the more difficult. The chin is like a hook. Imagine a person without a chin. He could just pull his head out. Especially if they are sweaty.

[3455434687]

I see what you mean. I agree, "once they get under your chin, it's hard to slip out" - I also agree that "he could just pull his head out" - but in both cases, only if the head/neck grip is the primary grip, and there's no leg/body control.

In my experience, leg and body control make or break a RNC, not head/neck grip: https://en.wikipedia.org/wiki/Rear_naked_choke#.22Body_Lock_... . It's way easier to escape a RNC that neglects leg/body control whether or not they've passed the chin: https://www.youtube.com/watch?v=JR2e0IsqhrQ , and the chin is an important part of the last-ditch defense.

...which is a long way of saying, I'd rather fight a dude with no chin, and if there were some option to temporarily remove my chin while grappling, I'd still decline, for performance reasons :)

I'd love it if a more experienced MMA player could chime in to confirm or deny our suspicions.