With my experiences with the ranking system, it seems to work in cycles. In a given session, you start with a cycle of pretty even games, then you start winning more and more. The issue here is that as you keep winning and your rank rises, it begins matching you with higher ranked players. Eventually these players' skill outclasses yours, which causes your losing streak. I think these streaks are just indicators of if your're improving or not though, because if you're getting a higher rank after each losing streak, it just means you're getting better. Need to work on writing things like these better.