[devonin]

Okay let me try this.

Your skill rating is based on the scores of the 15 best songs you have a score recorded for.

How good your score is, is based on the "AAA Equivalency" of the song, that is to say, there's a formula that takes your score and say "This is as good as a AAA of a song of difficulty X"

So if you got a AAA on a song with difficulty 27, that would have a AAA equivalency of 27

Whereas if you got a score of say, X-4-0-0-0 on a 27, that has a AAA equivalency of 24.37

So only the highest 15 AAA equivalencies you've earned will contribute to your skill rating, and thus ranking.

The 15th best score you have is a 36.30 equivalency, which means no score on any song below difficulty 36 can possibly increase your ranking, and only extremely good scores on 37-40s will.