I personally wasn't a fan of the 1-50 ranking system.
As Batman stated, win five matches, one rank up. Lose one match, one rank down. I feel (with the exception of FFA playlists, of course), that this was not a fair evaluation of "skill". Simply because you're on a team for the most part. Not on your own. Therefore a lost match often reflected the poor performance of a team as a whole; not a certain individual.