[Professor S]

Try appraoching it as honest questions about his reasoning for your grades. Anyone who grades someone else's papers should at least be open to the discussion.

And for the record, having a TA grade a professor's ESSAY TESTS based on his lectures is laughable at best. If it were a multiple choice or even short answer test, I could see it, but an essay test?

So a TA is grading your essay's, which are arguments based on your professor's lectures? How the fuck does that work without bias overwhelming any kind of honest quantatative evaluation?