Hey guys, thought I'd weigh in on this.
It's always been my opinion that one of the main draws of doubles is the sheer variety of Pokemon and strategies that can be used successfully. To that end, I'd like to suggest a somewhat unusual set of metagames.
In singles, there are relatively few roles that a Pokemon can have: Tank, Wall, Sweeper, etc. Naturally, there are a small number of Pokemon that are the best at those roles. Hence, each tier concentrates on a relatively small number of Pokemon. This in turn promotes the creation of lower tiers. It only makes sense to use Pokemon X if Pokemon Y isn't available. But then these Pokemon in turn are the best, prompting the creation of another tier below that.
In doubles, the situation is quite different. Very few Pokemon are almost strictly better than another and the number of 'roles' is near countless. Because of this, we have the potential to reduce the number of tiers necessary to include a very large variety of Pokemon. We still need more than one, because no matter what a cool niche ability your Cherrim or Murkrow might have, it will not stand up against a team of legends. Believe me, I've tried. However, I contend that to make over 98% of fully-evolved Pokemon viable, we will need only two tiers.
The top tier starts with no banned Pokemon at all. This caters to the players who like the heavy hitters and no-holds barred style of JAA and who don't mind a pretty centralized metagame.
The bottom tier starts with all legendary Pokemon banned, along with Dragonite, Tyranitar, Salamence, Metagross, Garchomp, Hydreigon, and Volcarona. Just to make it clear, I'm not advocating banning legendary Pokemon because of their label of legendary. I have found in my testing of various metagames in the 3rd and 4th generation that almost all of these Pokemon tend to center metagames around themselves to what I consider an unhealthy degree. In other words, these are Pokemon with a combination of enough hitting power, bulk, and speed to make most other fully-evolved Pokemon obsolete. There may be exceptions, of course. Say Regice is found to fit into such a metagame without warping it significantly. That's all well and good and it's what suspect tests are for. I'm simply suggesting this as an initial, easy-to-remember starting point.
I also advocate the following rules:
- Choose 4 Pokemon from your team of 6 after seeing your opponent's team
- Species Clause
- Item Clause
- No evasion clause
- No OHKO Clause
- No Sleep Clause (at least to start)
I don't want this thread to get too TL;DR, so I'll save my reasoning on these for later posts, once people have had the chance to respond.
EDIT: Just to be clear, here are the Pokemon I propose banning in the lower tier at a glance (pictures). They'd still be available for use in the higher tier.