Grade cutoffs / ragesoss
In my own experience, it has been rare to be on either side of an assignment (doing it or grading it) that had a very specific marking scheme. My very first professor in a programming class was one of the exceptions: every one of his assignments broke down exactly how each mark from the total could be obtained. This was hugely beneficial to me as a student, because I knew exactly what was expected. Perhaps it was even more beneficial to whoever had to grade it, since they essentially got a checklist to go through, allowing them to evaluate each assignment in the same way.
I often hear objections to this sort of scheme, the biggest being that with a checklist, students have too much spelled out for them. I disagree — if the scheme is done correctly, it should not take away the need to think. If students are able to use the marking scheme to get a perfect grade, then the work that results from that should be exactly what constitutes good work, demonstrating the student learned what they were supposed to. Besides, some of the marks in the scheme can be reserved for more subjective assessments, such as how creative the assignment was.
Creating a really good scheme takes a lot of effort and time, but if the person who created the assignment, and thus knows it best, doesn't do it, the grader will. Chances are, the grader isn't going to do it formally; it will likely happen subconsciously as they go through each assignment, noticing issues here and there. And that will make it difficult to be consistent. It also requires either writing out a lot of specific feedback that helps justify the grade given, or assigning a grade somewhat arbitrarily and hoping the student doesn't come back to ask where it came from.
I really believe that a good, specific marking scheme benefits everyone in the long run. I used such schemes when I taught without realizing how important they were at the time, and I am vowing to myself now that I will continue to do so.