In middle school, I got in LOADS of fights (though they were all one on one). In school, it was usually with the older school jocks, or skaters. Outside, it was with random groups of Saudis.
In high school, I started trying to avoid fights, since it started getting serious, and I wanted to avoid suspensions. I only got in three fights in high school.
Here's a couple of noteworthy fights:
1. Middle school. On the bus, there's this older school jock who likes to push around younger kids. I stood up to him, so he would pick on me more often. Eventually one day, we got into a shoving fight. So he told me he's going to kick my ass afterschool on the bus. So when I rode the bus, he was waiting. Before I knew it, he hit me in the face. Now taking this guy head on would be stupid of me, since he was taller and bigger than me (not to mention I've seen him beat kids my age pretty bad). So he was about to charge when I kicked his kneecap. At the same time, the bus made a turn, which caused him to stumble and fall. There's no way I'll give him the chance to get up, so I kicked him with all my strength in the back. Instead, I hit his kidney. He couldn't get back up after this.
2. High school. A group of guys were playing soccer, and they kicked the ball, which came to me. I kicked the ball back, and got some guy in the back of the head. I tried to apologize, but before you knew it he was throwing punches at me. Now I wasn't going to hit him back since I realize I provoked him. So instead, I had to force him into submission. So I managed to swat his arms away for a second before getting him in a headlock. I managed to take him down afterwards and pin him, which forced him to give up. We're cool now, though.