I guess I should be the one complaining as KC-KC-Scout-Scout-Scout's opponent...
(I also got unlucky by you using Saturday's instead of Sunday's leaderboard - I deliberately played lots of games on Saturday to regain previously lost levels for the tournament ranking and did in fact gain two which would have put me on spot 22 instead of 31... But you did announce to use "rankings on a date of our choice" (although I expected that to be Sunday), so that is OK of course. I guess you needed more than a day to process the data.)
the rankings were pulled saturday afternoon. it took a good bit of effort to set this up and get things organized (even split between 3 people) and having the bulk of the rankings in place saturday freed up sunday to clean up any messes and get the brackets in place.
But putting the underscore-oversight aside (that can happen of course), how did you (plan to) rank people who weren't on the current leaderboard, anyway? Just take their last entry? In that case they get a potentially big advantage out of not having played new games because they effectively froze their old level and weren't subject to level degradation by variance increase over time.
i'm far from convinced, as this cuts both ways. using mean skill could easily help those players instead of leveling the field. if they haven't played in a while then they likely are not going to be at that same skill level they were 2 months ago, and they are getting a nice seeding boost. and of course a player can get to a nice level and simply camp there and play on an alt.
and remember that you stay on the leaderboard for a full week since your last game, a span in which you are likely to drop about two levels. this offers some compensation drop for those who haven't played in a while.
I would therefore strongly suggest next time you either rank by mean skill (my preference) or you absolutely require people to play at least one game in the current week and don't let them take part if they don't. Both solutions seem a lot fairer than rewarding people for not having played current games.
from the rules: Please be sure to play at least one game on Isotropic this week so that you can appear on the leaderboard.
we did tell people to do it. forcing them to do anything is difficult though, and i think is a potential source of too much drama. there are good cases to be made for both mean skill and level, but i don't think that the case for mean is strong enough to lead to a switch at this point.
using mean skill would function better in a tournament like isodom, where the players are typically A. a little higher ranked and B. playing more regularly. the DS.com championships have a much broader appeal, and you need to adjust accordingly.