Okay. You are about to engage in a fight. You can decide how serious the fight is. But the target is someone who is as big and as intimidating as you, if not more. You could explain how you might kick someones ass smaller than you or dumber than you, but i don't think that is as realistic, or as fun. I mean yeah, you could kill anybody easily with a high powered sniper rifle and scope, but usually the more dangerous fights, and more realistic fights are ones that became serious about 20 seconds ago.
Personally, I am a weak, slow, unskilled, and slow witted kind of guy. If i got in a fight, my only chance(besides running, or talking my way out of it, or having somebody else stop it) would be if i managed to get somebody else on the ground before me, and then beat the shit out of them with a chair. If they got me down first, i don't think i'd be able to turn it around.