how the CS:GO Ranking System works, at least as far as we know…
Vitaliy Comment: https://www.reddit.com/r/GlobalOffensive/comments/2g3r4c/the_ultimate_guide_to_csgo_ranking/ckfhfir/
Glicko2: http://www.glicko.net/glicko/glicko2.pdf
How to Rank Up in CSGO