ASCENSION POINTS & PERFORMANCE RANKING

You know, if I get 60 points in Ascension and my team wins, I should probably get an S. What does it take? 100 points or maybe I should do like the Kha Zix and just go for a sweet KDA ratio and lose? Maybe then I'll get my S? I don't know what forumulae Rito uses but it doesn't seem to work unless you have only 3 deaths and at least twice as many kills. I feel like I've got an S only once for a beast like tanking performance.