I'm sure this has been discussed sometime in the past, but I haven't been around long enough to hear the arguments.
Why do we not implement a sliding scale of sorts to the ratings, to help prevent the lag mentioned by Chris. This would be especially useful for touring players and those who play a LOT of rounds in a 12 month period. Fast improving players who play a lot of tournaments in a 12 month span, will have low rated rounds as part of their rating, that were played a long time ago (in comparison to their current skill level). Their rating does not reflect their true skill level because of these rounds that are over 6 months old, but less than 12 months old.
Take myself as a prime example. My current rating is based off 62 rounds. However, my most recent 33 rounds are considerably better than the other 29 rounds. My rating can not catch up to my current skill level until I push those 29 lower rounds off my rating. If I continue improving like I want to, then by the time that happens, it will be time for 33 rounds to be pushed off because they would then be bringing my new and improved rating down. Hence the lag, which is even more noticeable to these fast improving young guns that are appearing.
A sliding scale limited to 30-40 rounds of data would be sufficient to get accurate ratings and keep up with a player's current skill level. If a player has not played enough rounds, then nothing changes and continue using data from the 12 month span.