My win rate is 48% with 3000 solo games at quick play. I count the win/lose and doing my own analysis then the accutual my win rate is 48% with whole 3000 games. Moving Average(500 games) has 55% ~ 42.5%.
I think these analysis shows us the matching for solo players is broaken. Note that my rank is Plat., so if its just my skill is too weak then the rank system is broken because my rank should be Broneze.
Your winrate has nothing to do with your mmr. They’re tangentially related at best.