Hrqls: I've seen this quite a lot, where I'm playing someone in 2 game, we split, and both our ratings end up higher than before. And no other games are completed between the 2 (which is the obvious thing to check first).

The explanations are not sufficient, if someone has played more then their rating would decrease and increase slower, but that doesn't explain the anomaly. Winning and losing streaks are not included in the calculation, only current rating.

So anyone have a mathematical reason why this might happen?