Max Hoberman on Twitter: "@Supascury A pair from Microsoft Research designed Trueskill, then the Live team deeply integrated it into the service for 360. I designed the ranking system for Halo 3,
Halo Infinite Ranking System Explained: Onyx, Diamond, Platinum, Gold, Silver, and Bronze - GameRevolution
Valorant Ranks: Ranking system, tiers and whether ranks reset in Valorant explained • Eurogamer.net