Just now posting in this thread after glancing over some things (late to the party again, I guess), but I want to try to shed a little light on another end that might be glanced over sometimes.
When building a full Baton Pass team, there is typically an already "good" Pokemon on the receiving end of the chain, typically something like Kyurem-B or Mega Mawile that need a little help in one stat or another. I...once had a Baton Pass Chain team for "teh lulz" and found that I could easily win without knowing much about the team itself. Just know "use x when y" and "go to this guy when z". This team utilized Espeon, Mega Scizor, Gorebyss, Gliscor, and Smeargle as the Baton Passers. The monster that would receive these boosts?
It then proceeded to annihilate Thundurus, Landorus-T, and Keldeo with ease before the opponent forfeit. Replay: http://replay.pokemonshowdown.com/ou-95094767
Yes, Rampardos was the one using the boosts to destroy the team. Rampardos. A Pokemon forever doomed in the lower tiers, never thought to come up.
Knowing some of the other users of Baton Pass, particularly Scoliopede and Mega Mawile, I want to use the judgment I had with this team and the different possibilities.
1. Do Nothing
Right...not going to happen.
2. Limit Baton Pass to three Pokemon per team.
This seems like it would be a relatively fair option at first. You can only have three with it? Sure--that's fine. We then run into a different problem: Scoliopede, Espeon, Baton Pass FILLER (could be Mega Scizor, Gorebyss, Gliscor, etc.), Ditto/Recipient/Support, Ditto/Recipient/Support, Ditto/Recipient/Support. It turns into another Gen IV Garchomp ordeal where teams dedicated to Baton Pass teams would be running the same things in order to crush the opponent somehow. This opens up new ways to use the team and new ways support a smaller chain of Baton Pass that will limit itself to, typically, Speed, Attack, and Screens (which is scary enough on its own right considering that it's really all you need). Is it easier to deal with? Somewhat, but it's still an issue when you have up to THREE recipients for the Baton Pass team that could potentially wreck instead of only worrying about one--a double-edged sword, if you will.
3. Ban Baton Pass in conjunction with Speed Boost and Magic Bounce.
Once again, it sounds impressive on paper. This would remove the threat of Espeon and Scoliopede almost entirely by disallowing them to boost their allies. On the other hand, though, this would only bring up other threats to the table. Venomoth would rise up to the challenge of its rivals as a Quiver Dance Passer, Vaporeon would patch up with Acid Armor, massive Substitutes, and Wish, Togekiss would cripple the opponent with Thunder Wave and pass a boost to an ally, Celebi is Celebi, and Zapdos received Baton Pass as a Gen III Event Move and can pull a job similar to Togekiss. It would merely mean that more and more Pokemon would be used in order to cover the holes that would be made. It's the slightly more effective approach in my eyes, however.
I'd personally go with option 3 and Ban Baton Pass when combined with either Speed Boost and Magic Bounce
, but I'd first have to work up the ladder to get a spot. That's just my input, though.