Same story for me, but with a difference. When the jocks wanted my expertise, I would write their homework essays for them, and I charged for it. They were afraid I would make it look too professional, so I added a few misspellings to make it look like their work. For $20 I would do a single paper, but the really good work would cost them up to $50. (You don't respect something you get cheaply or, even worse, for free.) This was good money back in 1964. The beatings stopped, I got respect, and I never got caught. Nor did my "clients".
I took care of one individual, a real asshole, who sat behind me for two years. He had tormented me by punching me in the back just to hear the sound it made. The teachers smiled and let him get away with it. He spent his time outside of class drinking and whoring with his Mafia wannabee buddies.
Not bothering to study, he needed help on exams. If he didn't know the answer, he would tap me on the shoulder. For example, if he wanted the answer to #34, he would tap me 3 times on the left shoulder and 4 times on the right. I would reach behind me and tap him on the knee once for "A", twice for "B", etc. This should have kept him off my case, but it didn't.
By the end of my sophomore year, he was asking for answers to practically every question. Once I gave him a deliberately wrong answer, and he punched me on the back. So I gave him another incorrect answer, but one that might be right. He took the bait. In those final exams I fed him wrong answer after wrong answer. Bottom line -- he flunked out.
Do not f*** with nerds! We get our revenge eventually.
Unfortunately for the most part the teachers didn't seem to see what was going on or at least not to care (they may have just written it all off as "boys will be boys").
One of the scariest things about Stephen King's It (1990) was the way the adults just stood around and let terrible things happen. I think that's one reason that movie scared me so much--it hit too close to home. (It certainly wasn't the giant wolf spider! Who doesn't love wolf spiders?)