Bully For You
You know a Biff Tannen, even if you've never met anyone named Biff. Their name could be Miranda, or Regina, or Jordan.
This person has a ton of insecurities. The only way s/he knows how to communicate is through verbal or physical abuse. They bring other people down in order to build themselves up: a classic bully.
The world is populated by Biffs. The creep in your office who corners you in the break room? Biff. The guy in the bar who won't leave you alone, even though you're clearly out to have a good time with a couple of your girlfriends? Biff. That overbearing boss? Biff again.
The only time we really love Biff-types is when they're a movie villain. Because it is so much fun to love to hate them. And it is so delightful when they get their lights knocked out or slam into the back of a manure truck. The bigger the bully the bigger the fall.
Here are a few of the items on Biff's bully résumé:
-Coerces George into doing his homework and, years later, his work reports
-Drinks and drives; then, after smashing up a car (obviously), blames a "blind spot"
-Manhandles women who are clearly not into it
-Travels everywhere with a pack of simple-minded goons to do his bidding
-Gets physical with guys who are clearly smaller and weaker than he is
-Has a jerk haircut. (Is that okay? Can we just hate him for his hair? Because we really want to hate him for his hair.)
Another reason to love Biff is because he gives Back to the Future one of its main conflicts: good vs. evil. We've already established that Marty is the "good," and Biff makes an awfully strong case for "evil." We're kind of surprised he doesn't carry around a red light saber.
"Make Like a Tree and Get Outta Here"
If Biff is Marty's opposite in the "good v. evil" department, then he's Doc's counterpart when it comes to brainpower. As in: he has none.
Some of Biff's stupidity is used to humorous effect, like when he messes up a simple saying such as "Make like a tree and leave/leaf," which instead comes out, "Make like a tree and get outta here." We almost feel sorry for the guy.
At other times, his ignorance is more infuriating, like when he's too incompetent to do his own work so he has to pressure the class nerd into doing it for him. (Although, according to Strickland, George is a slacker, so… is having him do your homework for you really the best idea anyway?)
A New Man
Several characters make drastic transformations from the old 1985 to the new 1985, but maybe none as dramatic as Biff. He goes from a sleazy, abrasive jerk with a toupee to a groveling, servile chump with a toupee. At least the toupee is consistent. We wouldn't be able to handle any more change.
But did that one punch really make such a difference?
It's tough to imagine Biff not going right back after George the second he came to. But it might not have been the shattered jaw that changed Biff as much as the utter humiliation of being flattened out by a guy wearing a pocket protector. Once he regained his senses and his cohorts brought him up to speed, he might have been too ashamed to show his face for a while.
It may have been a gradual change but perhaps that singular event really did change the course of history. Biff might have gotten a little gun shy, suddenly wondering if any random weirdo or nerd might be capable of retaliating and therefore abandoning his usual bullying tactics.
And maybe he saw something in George's eyes that night that scared him. So that the next time he encountered him, he hung his head a little and shuffled off in the other direction rather than decide to confront him.