My approach is that if a trainee attends a number of matches either with success or manages to stand ground at decent level against better opponents (= not to be ko-d cold in the 1-st round) then he will automatically receive a grading depending upon the level. His sparring partner or closest technical/strenght match in the gym will also receive the closest rank below, as no fighter is built upon only himself and the coach but upon the skills of the team. So one who fights will have his share and one who doesn't fight but contributes to the building of a fighter will also have it. People with good technical and coaching skills are promoted separately if they help to the coaching.