ジムリーダーの城　対戦考察Ｗｉｋｉ

Baton Pass performs Sweeper setup on its behalf and reduces the burden on the Sweeper regarding with switching, allowing for sweeping which would not be possible with a single Sweeper.
Just like JoltWak (Agility Baton Pass Jolteon + Sword Dance Marowak), it is a terrifying strategy, which if you do not take measures, can achieve sweeping and cause you to lose.

I categorize and introduce the benefits (functions) of Baton Pass.

Using Baton Pass makes it possible to perform setups using Setup Moves which the Receiver cannot access, increasing the number of options of setup.
In JoltWak example mentioned above, Jolteon is accessing Agility which Marowak cannot access and doing setup.

Even if the Receiver has access to the certain Setup Move, it makes sense to just transport the Receiver's Setup Move to the Baton Passer.
For example, if you give Sword Dance to Earthquake Rock Slide Marowak, it will either drop Hidden Power Bug (or Hidden Power Flying) which reaches Grass such as Exeggutor (and Heracross) or Fire Blast which reaches Skarmory, but by transporting Sword Dance to the Baton Passer like Scizor, it will not have to drop either.

When a single Pokemon does setup, it needs to withstand Attack Moves and the like while it's doing setup, but if the Baton Passer does Setup, the Baton Passer can shoulder that burden.
This is a benefit which is expected of bulky Baton Passers like Umbreon or Vaporeon.
For example, when Baton Pass to a Pokemon like Zapdos with Growth Vaporeon, Vaporeon will receive Snorlax's Double-Edge twice while using Growth twice, and then pass it on to Zapdos, which will receive Double-Edge once at that time. So in this example, Zapdos will do setup twice just by receiving one Attack Move.

Switching has +3 Priority, and Baton Pass has 0 Priority, so Switching will occur first.
When Switching
occurs, the switching window due to Baton Pass will be displayed after it is clear which Pokemon the opponent has switched to.
Also, if Switching does not occur first and the switching window due to Baton Pass is displayed, it will be clear that the opponent's Pokemon is staying.
This has the effect of eliminating the need for some of the predictions related with Switching including Double Switch, resulting in a reduction in the burden related with Switching in.

Because Baton Pass has 0 Priority, if the Baton Passer is outspeeded, the opponent will use a Move first, and then switching will occur due to Baton Pass.
This means that the Baton Passer can shoulder the burden on the Pokemon which is switched to when it is switching.
This is the benefit which can be expected of a bulky and slow Baton Passer.
For example, Umbreon can let Raikou use a Move first, and then use Baton Pass to switch to a Pokemon like Marowak.

In a few cases, the Baton Passer's Speed EVs and IVs may even be lowered to achieve this benefit.
While it is highly questionable whether this is a viable strategy in OU, Ariados is known in Japan as a Baton Passer which can pass Agility with being outspeeded with lowering his Speed EVs and IVs.

Here I'll list some countermeasures against Baton Pass.
And also how to outsmart them further.

For any Countermeasure, Baton Passer can outsmart it by using the appropriate Attack Move.
For example, Golem has countermeasures such as Roar and Explosion, but Vaporeon as a Baton Passer can outsmart it by OHKO it with outspeeding STAB Surf.

In addition to the appropriate Attack Move, you can also use Sleep Move which Smeagle can access to get the same effect.And, if you can accept to depend on luck, Accuracy detoriorate Moves (except against Haze) or Confuse Moves can get the same effect.

The important thing for those taking measures against Baton Pass is not to stick to one method, such as Phazing, but to combine multiple methods to taking measures with a broader and more reliable. As you can see just from reading the above, there is no perfect method.

Few Pokemon can access to Haze which can reset stage changes in stats, but it's the easiest to understand as a countermeasure to Baton Pass.
This is an example that's more known from Uber than OU though, Haze Quagsire is a great countermeasure to Growth Baton Pass Jolteon.

But there's one small problem with Haze as a countermeasure against Baton Pass. This is that it has no effect against rare Substitute Baton Pass.

Another problem is that Haze is difficult to use for active purposes.
One obvious usage is for Exploders like Muk to use it to counter Curse, but if that's all you want, it's better to give it Curse instead of Haze. This is because if the opponent doesn't do setup, you may threaten them with Curse + Physical Attack Move except Explosion.
However, in the case of Gengar, due to its typing, it can't increase its Attack Stage with Curse, so it's reasonable to use Haze to counter Pokemon like Curse Snorlax.

Roar / Whirlwind called Phaze (pseudo Haze), as its name suggests, resets the setup in the same way as Haze by forcing the opponent to switch out. Furthermore, this is also effective against Substitute.
This method also has the advantage of having a large number of accessible Pokemon, making it probably the most commonly used method for dealing with Baton Pass, at least more commonly used than Haze.
Not only is it used to countermeasure against Baton Pass, but it is also commonly used as a countermeasure against setup without Baton Pass. For example, Golem, Steelix, Tyranitar, and Skarmory use it to counter Curse Snorlax.

Additionally, this also be often used for active purposes, becoming especially violent when combined with Curse, Spikes support, and Pursuit.

However, Phaze has the problem of being too passive when used defensively against Setup Moves.

First, there is the problem that the Pokemon which performed setup will behave freely in a way which will leave undesirable effects on Phazer on the Turn it is phased.
For example, Sword Dance Scizor can leave +2 Hidden Power Bug (or, in an even more extreme case, +2 Hyper Beam) on the Phazer.
Also, apart from Attack Moves, I don't think this is viable in OU, but in Japan it is well known that Redian can leave Reflect or Light Screen.

Second, this can lead to undesirable Pokemon switching in for free.
For example, if Raikou uses Roar on Agility Baton Pass Jolteon, Marowak behind it may switch in for free. Marowak can wall break even without Baton Pass, which is never a good situation.

Explosion is useful not only for wall break, but also for emergency defense.
And the function of emergency defense is also useful against Baton Pass.

However, this can be outsmarted by Protect, Normal Resist (Scizor), outspeeding Substitute / Acid Armor / Barrier / Charm / Reflect / Curse etc, or out speeding Baton Pass to Normal Resist.
And, since Explosion is a Move which can only be used once per Pokemon, it is possible to be outsmarted simply by predicting being used Explosion and switching into a decoy Pokemon.

Sleep Moves are similar to Explosion. It can also virtually disable the opponent's Pokemon's functions, making it an effective countermeasure against Baton Pass.
Furthermore, since Sleep Moves occur effect immediately and Sleep Inducers are not likely got outspeeding OHKO by Baton Passers due to its stats and typing, it is rarely countered by Baton Passer's Attack Moves.

However, this can be outsmarted by outspeeding Substitute or Miracle Berry.
And, most importantly, if your Sleep Moves are absorbed by Status Absorber and Sleep Clause turns on, this method will no longer be able to counter the threat of Baton Pass.

As a side note, this can be more effective in the certain case when combined with Thief.
Specifically, a Thief Lovely Kiss Jynx / Nidoking lead is effective against a Miracle Berry Spore Smeagle lead.
(Turn 1 Thief -> Turn 2 Lovely Kiss)

In some cases, it may be possible to defeat both Baton Passer and Receiver by doing setup with a specific Pokemon while Baton Passer do setup.

In particular, Curse Snorlax (Earthquake or Resttalk) is often a counter to Baton Pass, and Baton Passer needs to take special measures to outsmart it.
To outsmart this you need methods like Acid Armor Growth Baton Pass, Curse Baton Pass (Sword Dance may be good too) + Machamp, Baton Passer's Charm + Receiver which can defeat Snorlax like Machamp or Vaporeon (note that defense stage is increased), Curse Roar (Curse and Roar can be used by either Baton Passer or Receiver).

And as another example, the sample Agility Baton Pass team is super vulnerable to Curse Heracross.
Also, in JoltWak mirror matche example, there is the case where switching in Sword Dance Marowak can be a good countermeasure against Jolteon.

It is effective when it is outspeeding.
For Alakazam which is the most main user of Encole, this can deal with every Baton Pass except Jolteon's Baton Pass and Agility Pass.
Jumpluff also has enough speed to counter any Baton Pass except Jolteon's Baton Pass and Agility Pass.

Alakazam can sometimes predict Snorlax's Curse (or Rest) and switch in to use it to dismantle the opponent's team.
Also, there are many Special Pokemon which can't 2HKO Alakazam without setup, so it can check Pokemon like Vaporeon (you should use a Move like Toxic in conjunction with it to consider the possibility of critical though).
This is especially meaningful for Stall Team.

Another example is Jumpluff using Encore in conjunction with Status Ailment Moves (Stun Spore or Sleep Powder) and Leech Seed, to support Pokemon like Marowak, Quagsire, and Snorlax.
If you use Leech Seed after enforcing any move other than Attack Moves (except Earthquake), your opponent will be forced to switch out, making it easier to spread Status Ailment.

Baton Pass inherits not only good effects but also bad effects.
This can sometimes be used to counter Baton Pass by using Status detoriorate Moves.

For example, if Receiver is Physical Pokemon, using Charm on Baton Passer can be a countermeasure, such as using Charm on Umbreon against Agility Baton Pass Jolteon + Marowak / Machamp.
However, this can be outsmarted by things like Special Receiver, Substitute, and Belly Drum.
(Note that something similar to Charm can also be done with Reflect and Light Screen)

Also, although this is more situational, there are times when Screech can be utilized.
For example, in Screech Earthquake Tyranitar vs Agility Baton Pass Jolteon (there is Machamp on behind), Tyranitar can use Screech to force Jolteon to switch out.

Baton Pass also inherits Confuse and Leech Seed.
These Moves may be combined with Substitute to withstand powerful Attack Moves including conbined with setup Moves, and in that case also can be a countermeasure to Baton Pass.

For example, SubSwagger Jolteon can be a counter to some Baton Passes, including Growth Baton Pass Umbreon.
However, it is vulnerable to things like Agility Baton Pass to outspeed Jolteon, RoarKou as a Receiver to force a switch out while removing Substitute, and Bonemerang Marowak as a Sweeper to crush Substitute and main body at the same time.
Also, SubSwagger Zapdos which is more popular than SubSwagger Jolteon can suffer from Pokemon like Alakazam as a Receiver because it doesn't have enough speed.
(However, due to its typing, it won't be outsmarted by Bonemerang)

Also, Stun Spore / Leech Seed / Psychic / Substitute Exeggutor can be countermeasure against Baton Pass including Agility Baton Pass if you can hit Stun Spore to receiver without being hindered by something like Scizor as a Baton Passer, Substitute or Receiver's Miracle Berry.
For example, Agility Baton Pass + Marowak is countered by this.

Incidentally, Perish Song and Curse (Ghost Type) are also included in the inheriting target of Baton Pass.
These Moves may also become a part of countermeasures in specific cases.

This is more of a playing issue than team building.
There are cases whichv are important to limit the opponent's options with OHKO range Attack Moves.

For example, Rhydon can OHKO Jolteon with Earthquake, and Jolteon's Hidden Power Water can't (barely) OHKO Rhydon.
If Rhydon switches in on the Turn Jolteon uses agility, Jolteon will need to fear Rhydon's Earthquake and there will become a risk in using Hidden Power Water to predict Roar.
Therefore, Baton Pass will be chosen with a high probability, and using Roar will be an appropriate play with a high probability.

Using Attack Move on Baton Passer to wear its HP will increase the number of cases where you can OHKO it like this.
Wearing Baton Passer with Attack Move is often important in taking away its options (more accurately, making its play more predictable).