well, it's pretty much off topic for this forum, unless you were talking mantis only players.
otherwise, people that want to spar with other people tend to do just that...those that don't won't. your question is really rather vague.
the truth is, most people really don't want to spar regularly at the level of 'fighting'
Vs. a boxer: if you want to learn something about what you can really do with your hands, spar a boxer on their terms. Or, if you're really serious, i'm sure you can find a boxer who will be will to let you do whatever you think your game is as long as he can hit you as hard as he wants.
"George never did wake up. And, even all that talking didn't make death any easier...at least not for us. Maybe, in the end, all you can really hope for is that your last thought is a nice one...even if it's just about the taste of a nice cold beer."
"If you find the right balance between desperation and fear you can make people believe anything"
"Is enlightenment even possible? Or, did I drive by it like a missed exit?"
It's simpler than you think.
I could be completely wrong"