Ranked and banked are heavily flawed systems
(Post copied from Support, recommended to send here.)
Ranked and whole game generally is dull cus matches still tend to practically end in the first 10 minutes. It also feels like sometimes you just randomly get free wins and sometimes forced losses like it's all arranged and I have no impact at all. This is how I would sum up S7 ranked experience (Dia/Master/Chall Elo). No actual close teamfights, just other side overstatting so fighting isn't even possible. Despite the changes you have been making nothing has changed for me. The winner is easier than ever to predict in champion select and by early game.
What comes to banked system, 10 max games banked is way too little and it doesn't encourage to play a lot in a row. I have finished over 900 rankeds this season, it is more than enough. But I'm unable to take a proper break cus banked system orders you to play 10 games in 10 days. If I had just timed my playing a bit later, I could have grabbed free challenger rewards when the season ends at this point. But now there's still half season left and I need to just go through more rankeds even I'm fed up with that already and reached goals.
Banked system combined with the fact that you need to be a certain rank on a certain day to get rewards is annoying and serves only those who play small amounts or leave their LP rush to late season.
It's not an excuse that "We want players to be actively around whole season". I've been more active than most challenger players ever will. Not many of them plays 900 rankeds, they just do one per day so their LP would not dramatically change like it does for me quite often. In addition, why can one START playing ranked whenever but not QUIT it. My 900 games means nothing just cause I carried them out on "wrong days" and "too fast", meanwhile someone just plays 200-300 games in late season and gets same prizes. All this feels dumb.
What I suggest is either make banked games to have no stack limit or at least increase it lavishly. Also it seems harsh that someone can be challenger whole season long and suddenly have a few bad games and drop down when the Day of Selection is upon making him lose the better rewards. If banked system is fixed, there will be no problem in that, though. At the moment there is just no freedom to choose when you want to play the needed game amount per season (in Master+ Elo). If there is a fear that increased stack amount would make diamond players to abuse it in season's start, then just put it on after challenger tier is full or something like that.
