Board Thread:Game Discussion/@comment-31526827-20190123095543

ELO was designed for head to head (1v1 or 2v2, equal on each side) contests, whereas TrueSkill can handle any matchup, like 1v7 and learns more accurately.

https://wiki.faforever.com/index.php?title=Why_choose_Trueskill_over_Elo_%3F

https://wiki.faforever.com/index.php?title=How_Trueskill_works 