I'm not sure, I only have Level 5 Summoners so the top-ranked players have a clear edge over me when it comes down to average card power. Also when you win a match near the top of the rankings you earn 3 rank points while you most of the time lose 30+ in case you lose a match especially against players who are ranked below you. I also don't play 100% optimal since I often bend my deck around the daily quest. I have been thinking about doing one season playing my A-game each time while playing 30+ matches a day. Maybe I'll do that in season 49