I had one geography and pre-algebra teacher in junior high that was like this. She practically refused to give out 100% on any assignment or test, and as far as I know no one ever could. She took the time to pick out any little flaw. Word misspelled? You lost points (granted, that’s fair for place names in geography). Handwriting not typewriter-perfect? You lost points. Didn’t quite erase something to her standards? You lost points. Didn’t format a handwritten page precisely as she defined (and she was extremely precise)? If you’re lucky you lost points, but she often threw those away with a zero. Used the wrong type of pencil? Allegedly she could tell if it wasn’t written with a #2 pencil, and would throw the it away if it wasn’t. The best grade I got in either of those classes was 99.5%. What did I miss? One of my 'i’s had the dot slightly touching the rest of the letter. Real Umbridge character personality-wise too, more than anyone I ever met.

All this allegedly to prepare for college. So it was a shocker when I got there find out that I could straight up get 2/10 correct on a calculus test but still be graded at 80% because (read this in a slavic accent) “you made mistakes in algebra, but you know your calculus”. Go figure