When someone takes the term "bulky attacker" too far, Porygon2 is the result. Although Eviolite allows it to achieve some of the best defensive stats in the game, it seems as though it were destined to use that bulk in a tanking role. As a supporter, its extremely shallow supporting movepool, lack of Leftovers recovery, and lack of resistances all work against it, but it can function as a very bulky utility counter nonetheless, especially if it gains a good ability with Trace. As an attacker, its good Special Attack and access to Normal / Ice / Electric coverage allow it to pose a significant threat to the opponent, even more so if it gains a boost through Download or Analytic. Opponents should do everything in their means to wear Porygon2 down, or to scare it off with powerful Fighting-type attacks, before it dishes out too much damage. Porygon2 might have failed at going to space, but it will certainly not disappoint in the more down-to-earth UU metagame.
Porygon2 is one of the best tanks in UU thanks to its incredible bulk and the firepower to back it up. A Download boost sends Porygon2's STAB Tri Attack above the power of Machamp's DynamicPunch; while an Analytic boost is weaker, it still puts Tri Attack's power in the area of Swampert's Earthquake and Snorlax's Return. If such comparisons are not your cup of tea, perhaps a more direct approach will provide a clearer demonstration of Porygon2's destructive potential after a Download boost.
Even without much investment into Defense or Special Defense, Porygon2 is very difficult to take down, which forces the opponent to rely on persistently chipping away at its HP or using very powerful moves, particularly Fighting-type attacks from the likes of Heracross. Even switching into reasonably powerful attackers, such as Nidoking and Choice Scarf Flygon, is a piece of cake for Porygon2.
Here is the lowdown on Download: just as it is important to watch what you download on the Internet, it pays to know what Porygon2 can switch into if it wants to grab that precious Special Attack boost. Slowbro, Nidoqueen, and Rhyperior are obvious targets, but there are more subtle examples; Nidoking has base 75 Special Defense, which is lower than its base 77 Defense. Some other UU Pokemon, such as Suicune and Blastoise, have roughly even defenses but are typically EVed to be physically defensive. Still others have exactly even defenses; while some more savvy players will know to invest a point into Special Defense to thwart Porygon2's downloading antics, many players neglect to do this. Of course, all of this fishing for specific targets can be avoided by using the more calculus-friendly Analytic for your power (series) expansion needs, though it misses some of the guaranteed 2HKOs demonstrated in the above damage calculations.Team Options & Additional Comments >>>
This set takes Porygon2's immense bulk and makes it even more extreme. The goal of this variant of Porygon2 is to force switches and spread status by walling a wide variety of Pokemon. Its uninvested Special Attack stat and BoltBeam coverage are decent enough to maintain an offensive presence as well. Trace might sound like a stupid matrix operation, but it bolsters Porygon2's defensive capabilities by allowing it to "borrow" some great abilities from unsuspecting foes. Trace Magic Bounce to inflict Xatu with its own Toxic, or use Rhyperior's Solid Rock to sponge the attacks of its Fighting-type buddies more easily. Use Shaymin's Natural Cure to fix that time you switched into Toxic, or switch into the powerful Fire-type STABs of Chandelure, Houndoom, and Arcanine by copying their Flash Fire.Team Options & Additional Comments >>>
The most notable setup move available to Porygon2 happens to fit this determined duck like a glove. Porygon2 is rather renowned for being an effective Trick Room supporter and attacker, thanks to good offensive prowess and the bulk to use Trick Room over and over again. Trick Room generally requires a lot of flexibility to use, which Porygon2 has; it can bomb the opponent with BoltBeam coverage, switch to a sweeper, or use hit-and-run tactics. To get a good idea of how dangerous Porygon2 can be, picture someone strapping a jet pack on Andre the Giant.
All this said, having only two moveslots for attacks hurts considerably, as this set has to sacrifice either its STAB Tri Attack or one of Ice Beam and Thunderbolt. Tri Attack is a strong STAB that, after a Download boost, exceeds even the power of Machamp's DynamicPunch, and losing it will make Porygon2 less effective against some opponents, such as Rotom-H and Kingdra. On the other hand, ditching Ice Beam will leave Porygon2 less effective against Flygon and Rhyperior, while forgoing Thunderbolt makes Water-types such as Suicune a pain to take down.Team Options & Additional Comments >>>
Outside of the typical moves, Porygon2's movepool is rather redundant for attacking, and rather lacking for supporting. Shadow Ball can be used to fight Ghost-types, along with Hidden Power Fighting for Rock- and Steel-types. If Calm Mind users such as Suicune are a problem, Psych Up can be used to steal their boosts. Charge Beam can boost Special Attack, and is especially useful with Analytic, but the power loss against the usual targets of Discharge and Thunderbolt—namely Water-types such as Milotic and Suicune—should be considered. As it sports a mere 50 Base Power, Charge Beam only outdamages the other Electric-type moves at +2. Nonetheless, it is usable against defensive Pokemon.
Checks and Counters
Porygon2 is generally weak to five things: gradual damage, Ghost-types, Steel-types, stat boosters with high Special Defense, and moves that remove its Eviolite (Knock Off, Trick, and Switcheroo).
Gradual damage can come in many forms: Stealth Rock, Spikes, burn damage, Toxic damage, and even repeated attacks. Porygon2 has no Leftovers recovery to combat all this, causing its user's stylus or mouse cursor to twitch ever more nervously toward that Recover button. What's worse is that some Pokemon have enough special bulk to set up Spikes or Toxic Spikes on Porygon2 with little worry. These include the likes of Roserade and Scolipede.
The obvious problem that Porygon2 has with Ghost- and Steel-types is that they resist Tri Attack, and many of them are not weak against its coverage moves. Porygon2 can do very little against Dusclops and Sableye. The former can remove 39% of Porygon2's health per turn with burn damage and Seismic Toss, stall out Porygon2's attacks with Pressure, and even run RestTalk to nullify Toxic. Sableye can also be a nuisance, as it combines Prankster with Recover, Taunt, and Will-O-Wisp to kill off Porygon2 slowly. Registeel is immune to Toxic and can itself inflict Toxic on Porygon2; Empoleon is similar as even a Download-boosted Discharge does not 2HKO it.
Porygon2 is setup bait for a handful of specially bulky sweepers. Mismagius is the most notable, as it is immune to Tri Attack and can set up on Porygon2 with both Substitute and Calm Mind. Cobalion also resists Tri Attack and can set up Swords Dance or Calm Mind boosts. Despite the fact that Tri Attack hits them neutrally, Raikou and Suicune are also great candidates, though the latter might want to tread carefully around Download-boosted Discharge. Snorlax can set up Curse on Porygon2, but without Curse, it has trouble doing much other than forcing Porygon2 out with Whirlwind.
Of course, another option is just to smash Porygon2's face in with powerful Fighting-type attacks or moves boosted by Choice Band or Choice Specs. Choice Band Flygon is a good minimum here; even if Porygon2 is defensive and Flygon doesn't 2HKO it, Porygon2 cannot just attack it with Ice Beam, as that will leave Porygon2 at low HP itself. Choice Band Escavalier is a fine candidate, while Victini does not even need a Choice Band to destroy Porygon2, as it can blast Porygon2 with a fairly accurate Focus Blast or smash it with a very powerful V-create. Darmanitan is also strong enough that even the Choice Scarf variant will send Porygon2 running for its programmer. Finally, Fighting-types such as Heracross, Hitmontop, and Machamp are obvious candidates for duck-breaking. Special attackers should also not be forgotten; Rotom-H's Overheat will definitely leave a dent, while Choice Specs-boosted attacks from Pokemon about as strong as Yanmega (or stronger) will also do the job with the help of residual damage. Check for Trace before sending in Houndoom or Chandelure; in the event that Porygon2 has Trace, aim Hidden Power Fighting at it.
If all else fails, I heard that some Porygon2 stop functioning when you tell them that pi is exactly 3.