Originally Posted by Arsnlrob
2 guys on my team played together almost every match, 10 matches total. One guy goes 9-1 playing with nobody else. The other guy goes 9-3, playing 2 other matches with other partners and loses them both. Guess who got the bump? Yep the guy who LOST the extra 2 matches.
Given they played the majority of their matches together, the key factor here would be where they started the year. The 9-1 guy must have been lower rated than the 9-3 guy, so when they won, because the algorithm effectively keeps the difference between their ratings the same, the 9-3 got "pushed" higher and would always be higher rated.
Additionally, the losses may have been to really good players, or the 9-3 guys partner may have been lower rated so they were expected to lose and the losses didn't really hurt is rating.