[mpalmer]

So maybe there's an approach that weights earlier grades heavier if and only if the final exam grade falls short? E.g. if I get an A on the final, the C average I've maintained until that point matters less to my overall grade for the semester.

No system is perfect and there will be inadvertent and undesirable incentives to underperform one way or another, but I like the idea of a system that focuses on rewarding improvement.