To satisfy students endless curiosity about my "grading policy" here it is. Note that according to the Graduate School policies A and B are "satisfactory" grades whereas C and F are "unsatisfactory".
As you can see, it is quite simple (you knew it all along). The question remains, of course, what are "well above" and "well below" (the "cut-off points"). I cannot answer that, but maybe the following information would help.
The following grades were assigned by this instructor in his years at GMU. These numbers are for M.S. level courses only (i.e., 500-600-700 level), and include only students who took the final exam (i.e., other than W, S/A, N/A, AU, IN, etc.):
Remember: this average accumulated over a long period. It does not mean that a specific class will obey these numbers exactly.
And, finally, the average grade is 3.17 (precisely between B and B+).
So now you know!