In my bjj class i am a white belt, but i can tap the blue belts that i train with about 70% of the time. There is a white belt that started about a month before me and when we train it is 50-50. so belts sometimes dont mean anything. I have actually seen a blue belt tap my instructor (it was a lucky catch) but it happens. so it isn't about how much you know, it is about how effectivly and efficiently you can apply what you do know. In our class it is more important to perfect 5 or 6 techniques as opposed to knowing 10 mediocre techniques.