Ranking System

Please riot, You have to sort out your ranking system. I played well in most my games apart from 2 maybe 3 where I fed, but still get placed in bronze 5. It shouldn't go on the win to loss ratio, because if you have an 0/9 who fed a yi you just cant do anything. Also my friend was in platinum 1 last season plays a games against platinum's this season and didn't feed one game but lost some and got place in gold 2. Please sort it out.