competitive pokemon question?

There are 2 kinds of Baton Pass teams. First, the light Baton Pass team, and second, the heavy Baton Pass chain.

In the light Baton Pass team you typically have 2 to 3 Baton Passers (which the above guy noted) and in the heavy Baton Pass chain you have 4 to 5 Baton Passers. The surplus are Baton Pass recipients, which take advantage of the Baton Pass boosts to plow through a team. The Baton Pass recipients must be chosen carefully.

In both, you should lead with either Smeargle or Ninjask. Smeargle can lock an opponent in the game, put them to sleep, and Substitute to shield an ally from one hit. Then it can Baton Pass. Smeargle is very good against slower opponents, but against faster opponents, it will get promptly KO'd. Ninjask, on the other hand, stalls for turns while your opponent tries to demolish it, and during these turns picks up many Speed Boosts (at least 3) and hopefully a Swords Dance; although it is very good against offensive opponents, more defensive players can easily play around it.

Afterwards, you should Baton Pass to a teammate that can provide both Attack (depending on which side of the spectrum your sweeper will attack in, but Special Attack and Speed cannot be granted at the same time except from Smeargle) and Speed (only if you don't lead with Ninjask). Gliscor is one of the best to provide Attack and Speed, with Swords Dance and Rock Polish, as well as Taunt to prevent these boosts from prematurely being lost if an opponent chooses to Haze, Roar, or Whirlwind. Togekiss is your choice to provide Nasty Plots and Substitutes.

Once that's done, using your other Baton Passers as pivots (Umbreon could use Yawn to put an opponent to sleep after Spore from Smeargle wears off, Vaporeon could provide one of the best Substitutes in the game), you're ready to attack!

Whom is the best choice to destroy with? Metagross, the definite most solid choice, is unaffected by any stat drops your opponents throw at it, and rounds up with Bullet Punch, a move that will always hit first, backed up by many Attack boosts. Although unconventional, Cradily's unique effect makes it invulnerable to the effects of Roar or Whirlwind your opponent may try to throw at it. In a similar vein as Cradily, Octillery cannot be Roared or Whirlwinded out, and provides unique attacks as Fire Blast or Seed Bomb. Tyranitar can hit hard both physically and specially. Bibarel, unconventional as well, has an effect to double all stat boosts gained. Bibarel also has Quick Attack.

A baton pass team works by having the "Baton Passers", the "Baton Recipients" and possibly a Passer/Receiver in one.

The lead should be a Pokemon capable of a high percentage sleep move, or a combination of Trick/Encore and Mean Look. The lead should also carry a sub so that- if chain-baton passing, will give the first pass a free switch in.

Common moves to pass are Substitute, Swords Dance and Agility, as these moves provide for a decent sweep. However, some may opt for Acid Armor or other defensive moves.

Your passers should be max HP and defense/special defense, as their main purpose is to survive a few hits while buffing up to switch. Status moves are also helpful on them, as with - Yawn for example - you can force switches allowing for more boosts.

It's important to carefully watch what your opponent is doing. If they switch in a certain Pokemon on your passer, make sure it doesn't carry a move that can OHKO you.

The passing should either be done right off the bat by trapping/crippling their lead, or towards the end with a sweep. Thunderwaves are good support so your receiver can outspeed scarfed pokemon. Keep track of what the enemy is carrying and set yourself up to be able to handle each one.