Originally posted by nemesio
Instead of max rating for the past 30 days to determine eligiblity for a tournament, what about using an AVERAGE rating for the past 30 days?
I think this would defeat the purpose. Say I'm a rating 2000 player who wants to smurf my way into a lower-rank tournament, where I can likely win. I start tanking games left and right, and my rating immediately plummets. My average rating over the past 30 days starts to fall immediately, too, albeit not as quickly. However, my max rating stays at 2000 for the full 30 days, after which it starts to drop.
In other words, to purposefully lower my rating (for tournament eligibility), I would need to waste an entire month of losing on purpose before seeing any reduction in my eligibility rating. That's quite a bit of work, and hopefully enough to offset any potential tournament-winning pleasure.
EDIT: Perhaps a better example would be the case where I only have to drop a few rating points in order to be eligible for a tournament. I may be able to reduce my monthly average rating in time for the tournament, but I won't be able to reduce my my monthly max rating by losing on purpose.