http://www.savedbythebellreviewed.net/2016/01/06/the-new-class-season-4-recap/

Ah, another season, another year of The New Class that I’d rather forget ever happened. But yet, try as I might to forget, I really did sit through another twenty-six episodes of pure, unadulterated **** because, yes, that’s what it was. Not a single episode I truly like and at least one hit a new low for me.

And yet, this was even after a bunch of changes, both behind the scenes and in front. Gone are half of our characters from season three, again, replaced with fresh faces that will be with us until the end of the series. I don’t know how to sum up my feelings on these three. They’re not particularly irritating the way R.J. or Tommy D were, and Katie’s just as bland a character, if not more so, than Lindsay. But I have no emotional investment in these people, and I’m sure the people who were watching in 1996 didn’t either. After all, with this series’ track record, we could be replacing the entire cast for season five.

Screech became rich and popular to all new class students at the end of season 3. That led him to become lively and loosely entertaining beginning on season 4. But the reason why you all think that he grew annoying along the way is because the producers may have accidentally increased too much power on his character beyond the limit. Of course, the producers did went too far overdoing his character beginning on season 6.