S Ranks are broken

Was that other someone another zac jg?

Keep in mind that the grades are cattered to both champion and position. As a jungler if you didn't get above average dragons and/or barons for your champ you might not get an S no matter the KDA or cs. Also ward placements and kills may or may not count as well.

Damage dealt/tanked? Objective assists? Wards placed/killed? Could be a number of things, kda doesn't really mean a whole lot. Also if the team score is something like 30/5 then even going 8/0/15 might not be enough for an S. It takes into account for super snowballed games and if you're not really the reason for the snowball and just got the free ride..(EG: if you had a yi that went 15/0 and got the 1st 10 kills on the team, then fed the rest to teammates...)

I have 360k mastery point on zac and am rank 6 guess how I feel