Ranking system is broken. It seems to be purely based on wether you win or lose vs individual performance. While I think that a win or a lose should be a contributing factor, I do not think that it should weigh so heavily. I have had games with k/d +10 but went down in rank because I lost. Aggravating when you are paired with a "lesser" squad.
Also, I've seen players with neg k/d that are onyx tier 2! Being carried I guess.