My only problem with this series: Robby

I felt similar about both students. Robby especially went from pothead layabout criminal to chivalrous karate master in the blink of an eye. It wasn't believable that he could beat students who'd been studying karate for years to make it to the final. Meanwhile, Miguel went from a kind and gentle boy, who stood up to the bullies, to becoming a bully for no reason. It really felt like the scriptwriters decided they wanted the two characters to end up making those about-faces, but couldn't come up with believable reasons for it.

It's a shame, because for about the first 8 1/2 episodes the show was great, after which it fell apart.

He shows up at Cobra Kai and sees Johnny being friendly with Miguel. This seems to make him angry again and want revenge on Johnny for some reason. I don't get it. Why does it anger him to see that his dad is being a good teacher?

I gave this show a 9/10 rating on IMDB (for me Breaking Bad is 10/10).

The Robby character was "off" for me, because he touches the least number of other characters. All the other characters have interactions with good number of the rest of the cast. Miguel has a relationship with Johnny, Samantha, his friends at school, the bullies at school, and pretty much everyone who has ever incited some incident on the show. Samantha in particular seems to interact with almost everyone of importance. With Robby on the other hand, it's just him and his dad, and later on Daniel and Samantha, and those interactions are pretty sparse. Between him not having much cumulative screen time, and his character arc being developed in isolation (because his story thread doesn't cross paths with many people, unlike Miguel who crosses paths with many people), his character doesn't feel developed enough for his character arc to be entirely credible.

I agree. I absolutely love this show but if there is a weak point for me it would be Robby. I did found Miguel transformation into a bully realistic enough because we spent time with him and being bullied plus Johnny teaching plus girl heart ache and alcohol makes it a believable combination for these changes in the character. However Robby went from Jerk to good boy in a flash and I just did not buy the "good Robby" as much as I did "Bad Miguel" . I still care much more about Miguel finding his real self again in season 2 then Robby development under Daniel teachings. As a "good guy" Robby does not have the charisma Daniel had in the original films.

I felt the same way.

One thing that keeps bugging me. He gets the job at the auto dealer. A juvenile delinquent that smokes dope and does other drugs and steals and has friends that do the same. When asked why he got the job at the dealership he says "My dad is gonna lose his s---." Uh, ok.

Really? That's the best this criminal can think of to get under his dad's skin? I'd think robbing a bank or setting Johnny's car on fire would be more in character. But getting a respectable job is his solution to pissing off his dad?

I didn't like Robbie at the start, and the more he became the good guy, the more and more I hated him. I would seriously have been mad if they had him win in the end.

One thing I realized about Robby that I must admit, though: At least he had more training than Rey in both The Force Awakens and The Last Jedi, lol!

Another thing I just realized about Robby: he drops what, I believe, is the only F bomb in the entire series when he sees Johnny's flyer and says "...it's my fucking dad". This isn't a criticism, but it's telling that the writers chose to use, probably, their only allotted F bomb to reflect how Robby feels about his dad. Youch! I guess that's why, in spite of his efforts, it's gonna take a while for Johnny to repair their relationship.