Those aren't very descriptive.
Rank is based on your qi level WITHIN JUST YOUR BELT. The more qi you have, the better your rank.
For example, if you have 999 qi (one qi away from blackbelt), then you will most likely have a rank of 1. Once you get that one more qi though, you will have the lowest rank within your belt, because almost everybody else has a higher qi level.
What if you have the same amount of qi though? Well if your qi is the same as somebody else's, THEN your wins/qi ratio will come into effect. So say both you and one other person has 999 qi. If you have a ration of 60%, and theirs is only 55%, you will be rank 1, they will be rank 2.