10) The most obvious inconsistency was the morphing of Zach Morris' Indiana junior high to a California high school. It's hard on a kid to uproot like Zach Morris had to (especially after all the work he did to be a member of the uber-exclusive Rigmas). Of course, transition is easier when you can bring two of your best friends, your principal, and your physical school building. The good news was that the California location enabled the school to be called "Bayside." And that led to that brilliant cheer, "B Ba B Ba Ba Ba B. B Ba B Ba Ba Ba B " Go Bayside!" That must have taken dozens of seconds to write.

9) Speaking of best friends, the show makes reference to Zach and Jessie being friends their whole life. She must have taken 8th grade off because she wasn't around when the show first started. Kind of like the time she took senior year to test pilot season. Uh, I mean model in France. Traveling like that can be so exciting. So exciting. And scary.

8) Zack should be in jail. While we're made to believe he's just an incorrigible prankster, Zack has committed grand theft auto, kidnapping, racketeering, forgery, identity theft, mail fraud, and destruction of public property. The nicest thing he's ever done is cheat on his girlfriend.

7) No one can hold on to a family member for more than two episodes. Perhaps Mr. Belding's hipper younger brother Rod moved back home to Indiana. Maybe Jessie's bastard New Yorker half-brother Eric isn't talking to her anymore despite the gang convincing him to stay at Bayside. Maybe Kelly's parents didn't let her watch her baby brother Billy after Zack lost him. Maybe Zack's powerful yet uncaring father Derek was too busy with mergers and other businessy terms to spend time with him. Maybe Slater's tomboy/bombshell sister JD was sent to a convent. And maybe Kelly's sister Nicki disappeared when writers remembered that Kelly only had brothers. As if the show had writers.

6) Beloved pets don't exist until it's announced that they're beloved. First, there's Screech's parents' prized beagle Hounddog. Screech's parents named the dog in honor of Elvis, who they were such big fans of that they mentioned it in one whole episode. In the hundreds of scenes shot in Screech's room, Hounddog never existed – perhaps Screech's robot Kevin was a bit jealous of Hounddog. The real ridiculous one was Slater's pet chameleon Artie, who only existed in time to die.

"This is the most important thing in my life. I promise. Um, why don't any of you know about it? Well, Maybe there are a lot of things you don't know about me. YOU DON'T CONTROL ME!!!"

By the way, Screech having built his own robot is not an inconsistency. If there's one thing we know about dorky 15-year-olds in the 90s, it's that they can all build robots. Maybe next Screech can build Zach a cell phone smaller than a two-liter bottle (which he somehow kept in his back pocket, while sitting down).

5) Bayside can somehow afford a football team, track team, cheerleading squad, swimming team, oil rigs, auto shop, teen hotline, home ec kitchen, student store, ski trip, water polo team, ROTC, wrestling team, radio station, and yes, a restaurant. They must have saved all that money by only hiring seven teachers. And not building a second floor. 

4) When AC Slater's father was stationed in Germany, Slater apparently was inseparable from fellow army brat and then girlfriend Jennifer. Bayside must be in an army town because Jennifer became a Tiger for an episode. That's right " her father moved her across the world to the same town as her ex-boyfriend. Maybe in the one episode he existed, AC's dad told Jennifer's dad all about how wonderful the school was. What with the a football team, track team, cheerleading squad, oil rigs, auto shop, teen hotline, home ec kitchen, store, ski trip, water polo team, ROTC, wrestling team, radio station, and restaurant. Yes, a restaurant.

3) Mr. Belding has a secretary he keeps paging, yet the door to his office opens directly into the hallway. This door must not lock, since those wacky kids are always sneaking in and switching the files. The school's files, which are efficiently kept in a single, three-drawer filing cabinet. Probably because there are two-dozen students in the entire school and one of them is named Muffin Sangria.

2) Inconsistencies often happened within one episode. This is the least forgivable offense, as episodes really should be written by the people who freaking write them. One example is the gang's murder mystery. At one point, Zack suggests that "the butler did it." About ten minutes later, he refers to Screech saying the butler did it. How did NO ONE on set notice? I can forgive Lark Vorhies; she was probably busy, already planning how to destroy her face with an insane amount of plastic surgery.

And of course, there's the Johnny Dakota anti-drug ad. We see the gang shooting the end of the ad, and then they role the entire thing " but the end of the completed ad looks different than what we just saw. How drugged out do you have to be not to simply use the footage you shot? Come on guys " there's no hope with dope.

1) And speaking of drugs, the most memorable episode of the series was easily Jessie's freak out. Forget about the girls not being able to tell that the Irish old lady janitor was actually Screech. Forget about the fact that the girls suddenly became famous for a crappy ten-years-too-late rip off of "Let's Get Physical." Let's concentrate for a moment on Jessie Spano, the smartest girl in school, freaking out over basic trigonometry. IN HER JUNIOR YEAR. Good math students master trig in 9th grade. And she expected to get into Stansbury (The Harvard of the west). While we're at it, Zack got an impossible 1502 on his SAT. I actually got a 1502 and a half. And boy, was I so excited.