Unfair seeding
When I started to play LoL, after my first seeding I found myself in Bronze 4 (or 5). After whole season of climbing I hit Silver 1. Next seasons I progressed and hit Plat 4. This season was really hard for because of tons changes, but in the end I started to found myself with Gold players who doesn't know that Nasus Q hits AD damage, with tanks who scared to initiate etc. It feels unfair for me, because I've learned all this things long time ago, so why they're here with me in Gold?