Originally posted by dsb3
I think 30-day high is fair. It's long enough to discourage people from dumping points to enter an easier tourney round (do people do that?), but short enough to follow the player's course.
Actually, players did throw games to get into lower rated tournaments. That is one of the main reasons that it was added.
If you wanted to adjust for those that peak one or two games over a certain range, maybe do this...
Take the average rating over the last 30 days.
Average it with the highest rating over the last 30 days.
In addition to adding to server overhead, you would get a slightly lower rating that would be more indicative of the player's actually ability.