21/5/17 no S why is that?

KDA is only one aspect of the system used to determine your rating. It accounts for several aspects of your performance, with considerations of your champion pick for the role you are playing and the length of the game. Also, it is a rather relative rating, comparing you to other players using that same champion in the same role.

Most of the time a lower rating is a result of lower than average CS, lower wards/minute for support, damage dealt, etc.

Champion score ratings are calculated based on the average performance of other people playing that champion.

Because kills are least relevant factor when it comes to grading. What was your warding count? How many pink wards? How much CS? If its less than 6 per minute, u dont even deserve S. What about objectives? Did u stay for that juicy drake or did u chase that poor Janna or Sonna supports to get more kills? What about turrets when u ganked/roamed? Did u stay to take turret or did u just look around where u can get another useless kill?

Because ur a boosted animal.

CS