Been semi watching mma from Forrest Griffin in some absolute hellacious fight (Broner..Bonner?) and think the time on the ground avoiding chokes and limb wrenches..but still more controlled breathing or time bought..cannot be overstated. Arguably and this may sound nuts but boxing can be far more physical with pure stamina. A ref will break guys clinching ten times before making two fellas playing twister 'stand up'.