Analysis

In Dec 23, Gastrodon is one of the most critical pokemon to consider when building a team, even if you elect to not use it yourself. On the surface Gastrodon's role in the metagame seems obvious, it's the Pelliper switch in. Immunity to all water-type moves via storm Drain combined with a high base spd stat allows even a physically defensive Gastrodon to switch in on any of Pelliper's unboosted special attacks. Counterintuitively Gastrodon is not always the best answer to Pelliper. 

Although it has a decent base special attack stat, Gastrodon can be quite a passive Pokémon. Its privileged access to hazards, status moves, and reliable recovery can ironically hinder Gastrodon by turning it into a momentum sink. Top physical threats such as Gyarados, Tyranitar, and Durant can all come in on Gastrodon's status moves with relative comfort. Both Gyarados and Tyranitar, despite lacking steel or poison typing, can afford to come in on a toxic, either by holding alum berry or threatening enough damage in the short term to render the residual damage from poison unimportant of course. There are scenarios in which badly poisoning an opponent's Gastrodon switch in can be worth the risk, but such opportunities are not the norm and difficult to find. And if any of the aforementioned three Pokémon come in on Recover, Stealth Rock, or spikes, the Gastrodon trainer may find themselves in hot water. Durant, Gyarados, and to a lesser extent Tyranitar frequently ran setup and more often than not could set up in front of Gastrodon and still retain enough HP to either sweep or make very significant progress before fainting. 

(Durant sets without Spd EV investment cannot withstand a storm drain boosted attack unless they have a focus sash) 

What does this mean for the Shug's overall viability as a Pellipper check? It means that Gastrodon truly shines in the mid late game, when its switching have already taken some chip damage and/or hazards are already up. In the early game, extreme caution is advised. Double switching is as to an option available to Gastrodon, but that requires a good read on the opponent's team and play style which inherently carries more risk so if it isn't just the captain of the anti-Pellipper squad, what is Gastrodon actually good for? The answer is actually 3 fold; Gastrodon excels as a hazard lead, status spreader, and keeping physical threats in check. Gastrodon's excellent defensive typing coupled with the relative lack of leads or anti-leads with either grass typing or moves make it quite a popular and versatile lead. Although top threats can switch in on Gastrodon, very few would like to deal with it at full health. Appropriately invested Gastrodon sets can survive a boosted Morpeko seed Bomb and Eldegoss Giga Drain (or with a rindo berry) and threaten critical damage or fatal status in return. Gastrodon as a lead is nearly always a good choice into an opposing lead Pelliper, able to either force itouton scout its item. that is, unless, you have the misfortune of bringing physdet Gastrodon modest spes Pelliper. In that case, your sole avenue of recourse is to pray to every god you don't believe in and offer up a Magcargo to the elder slag as a blood sacrifice in the hope they reverse your accursed luck. 

 Okay, pokes aside, the actuarial solution is to send in the other most popular Pellipper answer, Tyranitar. Immediately replacing rain with sand reduces the power of water-type attacks by 2254-Grain boost#sandgpdt boost, and guarantees a small amount of chip damage on nearly all Pelliper sets. Most importantly, Tyranitar affords you the one thing Gastrodon never cast momentum and guaranteed progress. Tyranitar can threaten STAB knockoff so powerful that even opposing Tyranitar, Regirock, or Chesnaught must be weary of the chip damage. Because this is a National Dex format, Tyranitar maintains access to pursuit which it uses to force Pelliper to choose between the Scylla and Charybdis of risking an ohko or suffering an effective base 120 power more coming off a base 134 attack stat.

(this interaction changes in the mid- late game when more information is available and more chip damage has occurred. A Timid Pelliper set can outspeed any unboosted Tyranitar and even potentially threaten ako or invaluable chip damage.) 

Tyranitor can also elect to get up with dragon dance, accepting the chip damage in exchange for the potential to obliterate teams deficient of choice scarf Pokémon on priority. The traditional response to Tyranitar in this situation would be to immediately send in Chesnaught, but at high level play this is not the sure fire answer it used to be. Some Tyranitar. sets opt for Aerial Ace specifically to counter Chesnaugh and mixed sets with the same aim are occasionally observed. The presence of another Pellipper on the opponent's team can serve as a deterrent to Tyranitar's best switch in, Regirock, as its defensive sets are unable to defeat Pellipers because Regirock's only method of reliable recovery is rest + chesto berry, switching in on a knock-off comes with a steep cost. The ability to not only switch in on arguably its biggest check, but actually make progress against it is one of the factors which puts Tyranitan a step above the rest of the physical attackers in the tier Tyranitar is the most consistent way to deal strong physical, immediately threatening, damage in the December meta. Durant often needs to gamble with Hustle and is virtually incapable of tanking more than one special attack while Gyarados nearly always needs some sortef boost to deal the right amountef damages The previously stated base BY attack certainly helps, but Tyranitars natural balk, great offensive typing, and deep movepool all contribute equally if not more to its viability. Gastrodon, in comparison, simply cannot hope to offer the same amount of immediate offensive pressure. Fortunately, that isn't, its job as a lead. Its primary role it to set hazards,spread status, and/or scout opposing sets. 

Gastrodon Roles:

Gastrodon can serve as a hazard lead, a status spreader, a special wall, or (most often), a combination of all 3. A typical Gastrodon set will contain: a hazard move (spikes/stealth rock), Recover, Scald/Earth Power, and either a status move (toxic/haze/yawn) or a second attacking move (typically Scald/Surf/Earth Power). Ice Beam and Clear Smog are sometimes seen but aren't as common as the aforementioned options. Gastrodon is bulky enough to survive virtually any non-supereffective attack, and so hazards are nearly guaranteed to go up on your opponent's side of the field. If you see a Froslass on the enemy team, however, your best course of action is to keep Gastrodon in the bag lest it get shut down by taunt. 

If the goal is to use Gastrodon as a status spreader, an additional attacking move (or Protect) can be used in lieu of hazards. Heavy-duty-boots are advised on these sets, to facilitate easier switching unreliant on hazard removal. Spreading status is also a good way to maintain momentum after walling special attacks such as Hurricane or Surf from Pelliper. Sets optimized for tanking such attacks may appreciate leftovers or a healing berry in the item slot to increase longevity and potentially keep Gastrodon from being KO'd before it can use Recover. 

Written by Typhon

Grammar checked by Essence