Code: Wobbuffet moved from RU to NU Lopunny moved from PU to RU Altaria moved from PU to UU Leafeon moved from NU to PU Pidgeot moved from PU to RU Sableye moved from UU to OU Dragalge moved from NU to RU Salamence moved from UU to OU** Sceptile moved from NU to RU Mawile moved from OU to UU Houndoom moved from UU to RU Beedrill moved from PU to UU Metagross moved from UU to OU

As most of you know, the Smogon tiers were scheduled to update this month. For those new to our system, how our tiers work is that they're primarily based on usage (the names of the tiers, OU, UU, RU and NU, literally mean "versed," "ndersed," "arelysed" and "eversed"*): Pokemon that are used heavily in the tier above get banned from the tiers below.Usually the way we calculate the tiers is by using a strict cutoff, above which a Pokemon goes in a tier and below which the Pokemon is allowed into the tier below. The cutoff we conventionally use is the point at which you're more than 50% likely to encounter that Pokemon at least once in a given day of playing, if you play 20 battles a day. For those that don't feel like doing the math themselves, that number is approximately 3.41%. So that means if a Pokemon is used on 4% of OU teams, it's considered OU and is banned from UU, RU and NU.Furthermore, it is our standard policy to base this 3.41% number on stats weighted over the previous three months , with 5/6 of the weighting from the last month, 1/8 from the month before that, and 1/24 from the month before that (ratio of 20-3-1).Finally, for those who are familiar with how we calculate usage stats know, we weight our stats based on player skill rating , and we're calculating stats using a baseline of 1695 for OU and 1630 for UU, RU and NU. To eliminate some numerical anomalies, we're also throwing out teams where the player'sis greater than 100 (meaning they've had less than ~5 battles under their alt). This decision is detailed in this thread On top of the usage-based tiers we also have "borderline" or "BL" tiers, which are essentially Ubers banlists for the lower tiers. These lists ban Pokemon that aren't used enough in the higher tiers but are too overpowered for the lower ones. BL banlists are not subject to usage stats, except a BL Pokemon can, of course, move into a higher tier (from BL to OU, from BL2 to UU).Also note that a Pokemon cannot drop more than one tier per update cycle. Say no one used Charizard in OU for the next three months. That would drop it down to UU, even though it had no usage in UU for that period (how could it? It was OU).So that's how we usually do it.But this time around, there have been some... complications.Firstly there was the release of the new games, complete with new mega evolutions and new move tutor moves. Overnight Pokemon like Altaria and Lopunny went from atrocious to awesome. All of the stats collected before the ORAS release suddenly no longer reflected the state of the metagame.Secondly... the PS server lost a hard drive, and with it, all the logs and stats from the past several years. This is largely my fault--I stopped running backups about six months ago. And since I stopped posting the monthly stats in threads quite some time ago, that meant that there was no practical way to get the data needed to update the tiers, since I'd only be able to work from about 10 days' worth of data.The cleanest option to move forward would have been to not update the tiers at all this month and put off the update until February 1, when we would have two full months and one partial month of data. But (1) that would have put a lot of responsibility on the suspect councils of the lower tiers to figure out which new megas didn't belong in their tiers and (2) it would needlessly delay the drop of Pokemon like Mawile, which has already been waiting three months to leave OU. Still, we didn't feel comfortable basing the tiers for the next three months solely on ten days of stats in a set of brand new metagames, where players are still discovering the best movesets and strategies.So we worked out a compromise: based exclusively on the stats collected since the ORAS release, we would allow rises and falls only when the usage data wasoff from the status quo. I said earlier that the cutoff between tiers is the point at which you're more than 50% likely to encounter a Pokemon at least once in 20 battles. Well, this month,(6.70% usage), and(1.72% usage).This is far less than ideal, but it does allow us to perform some quick course-corrections without putting too much of the onus on suspect councils.We've also decided that we're going to do this again (with rise/drop levels a bit closer to 3.41%) in January. I apologize in advance to my fellow Wi-Fi players for whom monthly tier updates are a bit of a burden, but once February rolls around, our plan is to do a full, normal tier update, and we'll lock those changes in for a good three months. Thanks, everyone, for understanding! Feel free to post below with questions or concerns.Anyway, here's what you came for:Tier changes for December 2014: