What does it take to get an S+

here http://matchhistory.na.leagueoflegends.com/en/#match-details/NA1/2144443066/215750452?tab=overview i believe I obtained an S+ rank in this game as vlad use that to know what the game wants from you it judges you based on your kills, assists, minion kills, towers taken, dragon/barons, and wards placed.

Your grade depends on your percentile performance compared to all other players' performances on that champ in that role, so theres no absolute numbers required to get an S grade, you just have to do better than the majority.

If a particular champ in a particular role generally does poorly and you still manage to do an 'ok' performance, it's possible to get an S, while champs that potentially do extremely well in a particular role you can have a completely amazing game and still 'only' get an A.

It not just KDA that makes the grade.

Minion CS, wards place, wards destroy, assisting in taking dragon/baron, using your trinket, using the elixirs, and how many turrets you destroy/assist in destroying.

You can no 25/0/25 but if your CS is 5, place no wards, did not take a single dragon or baron, and never even damage a tower, you will not get S rank.

It's been discussed in many places, KDA is only part of the grade system. Common things people have noticed that contribute to your score:

Wards Placed Trinket Upgrade (i.e. did you do it) CS Objective Participation Kill Participation (your Kills and Assists vs total team Kills)

Then these factors are compared to other players' performances on that champion.

May have missed things, but the gist is, grade is more that KDA