Typical Master+ Player : " Just hard CC Katarina and you win"
Meanwhile at master+ http://www.lolking.net/champions/katarina®ion=all&map=sr&queue=1x1&league=challenger#statistics 60% win rate
Meanwhile at master+ http://www.lolking.net/champions/katarina®ion=all&map=sr&queue=1x1&league=challenger#statistics 60% win rate
To be fair, that's one day of results. Nothing changed from 4 days earlier when her win rate was 45%. That's normal fluctuation - if it hits 60% consistently then we have a problem...
One day win rates in master+ are worthless.
Challenger isn't a good source for win rate because the sample size is too small.