My anecdotal evidence says that the teacher makes much more of a difference than even the students. In my high school, every single kid that took AP Calculus go

My anecdotal evidence says that the teacher makes much more of a difference than even the students. In my high school, every single kid that took AP Calculus got a 4 or 5 because the teacher was great, and barely anyone passed the chemistry exam. In a competing high school not far away it was exactly reversed: there was an effective chemistry teacher and every kid got a 4 or 5, but somehow they struggled in calculus.