I had a math professor who did an amazing job at preventing cheating by making coursework more-or-less optional, and then exams would be 50% problems they’d inv

I had a math professor who did an amazing job at preventing cheating by making coursework more-or-less optional, and then exams would be 50% problems they’d invented specifically for that year, and 50% problems given ahead of time (you only needed to do half of 75% of the exam). If you “got it”, the problems he made up were always very short, whereas half of the preassigned questions were long and tedious. This basically set a hard cap of a B/B- for any student that wasn’t either wildly talented or engaging with the course material and getting useful feedback from the assignments. It was possible to pass with a C by cheating on assignments (looking up the answer and rewriting it so it wasn’t terribly obvious) and memorizing the solutions to the preassigned problems, which was honestly fair based on the rules he set for the course.