Being an only child (omg yes), I've never had any sibling beatdown experiences.
However, back near the end of freshman year, this one kid who I just wanted to strangle with a bullwhip decided to pull a little prank on me one day. They put partially chewed gum and all sorts of nasty stuff on my locker handle. Luckily I arrived there just as they were walking away, laughing their asses off. I stood there looking after them for a few moments while the rage began to appear inside me. I suddenly took off down the hall not really knowing what I was doing and I rammed into the kid's back with my shoulder so hard he fell to the floor and his backpack flew off his body and was vaulted a good nine or ten more feet down the hallway. Fortunately for me, there was nobody around to see this happen so I wasn't caught or anything.
He hasn't even so much as looked at me since then.
That's really the only "fight" in which I've been. You couldn't really even call that a fight seeing as I was the only one that did any hitting.
