Regarding Champion's Mastery and S Ranks

Hello everyone, as you can tell for the tittle I'm here to discuss the Mastery system, and furthermore the overall after match ranking ( A+, S etc..), and hopefully, attract the attention of a Riot Staff member. So the other day I was wondering how come I have played so much and gone into some mad killing sprees and still not a single mastery shard , and it makes me wonder, what is the algorithm to give an S rank after match, it seems that you need to go on a freaking killing spree, and not even then! As a main support it is really hard to get to mastery 6 and further. It seems like the kills have a greater impact than anything else, I'm talking as long as you get mad kills, it does't matter how many times you die, you probably going to get an S ranking, a** and that makes me wonder if Riot has taken a look at it, does it need a re-balance? ** Anyhow, I gave up on my mastery 6 on Thresh because no matter how many assist i was getting, **even if I didn't die not even once and got a lot of assists still i couldn't get S rank, ** and as i have mentioned before, you almost have to go on a killing spree to get the S ranking, and not even then! let show and example of last match i had 15/0/9 with 15/0/9 **Completely annihilated them and i didn't die not a single time, ** and here is the proof So I call upon the attention of the Riot Staff, and furthermore whoever wants to red this, that consider a re-balancing the ranking system withing the game, **and i'm not saying make it easier, i'm saying make it fair! ** when going as a support give more weight towards the S to assists, and give more attention to not dying in a match, take a better look at it, i have no further comments to make regarding this matter, so i would like to hear your opinion on this, thank you for reading.