How Defensive Counterplay is Real and Why Stall Is A Real Archetype
As far as I am aware, common opinion is that stall one of the worst archetypes because the offense is too good. When I say "the offense", I don't mean offense as an archetype but rather just the Pokémon. Main reason people say this is because MMX is able to run coverage for anything it wants and in its 4 slots can cover most of the game, and aswell there is too many sets answered by a few B ranked Pokémon. Now what I'm going to try to do in this post is prove that defensive counterplay is real on stall and that it's a good archetype.
Checklist
Here's a list of everything you will reasonably need to cover to help better visualise it.
-MMX

-Huge Power and No Guard Kartana

-PDon

-Harvest Slaking

-General MGeist coverage fishes


- Sunsteel/Geist/Fairy

-No Guard MMY

-General Special Photon?

-No Guard TSpikes Taunt MGar

-WG Sweepers

When I lay it out like this, it does seem more manageable. Building stall is generally just about stacking as many hard answers to these Pokémon as optimally as possible. For this reason stuff like Zygarde-Complete isn't actually that good on stall as it isn't a hard answer to most things on this list outside of potentially MGeist MMX and some WG sweepers, but there are other options who can do that and other things at once making them better options. I will go through everything here one by one and how you can answer them, and finally I will provide example stall teams.
MMX
While it's true MMX can run coverage for anything, it will not often run certain moves together and this can be taken advantage of, meaning for the most part you can wall MMX. It is however worth noting that Band MMX doesn't really have walls outside of certain Prankster SSap Pokémon, but not covering for it properly is more reasonable seeing as it isn't very common right now due to being prediction reliant, STag food, and not great into offense outside of First Impression which is exploitable.
The most optimal way to wall MMX is using Fur Coat Slowbro paired with a Pokémon able to answer Photon Geyser/Sunsteel Strike/Close Combat/Moongeist Beam MMX. Excluding Choice Band, FC Mbro is able to answer all MMX running some form of physical coverage for it, seeing as there isn't a 180BP non CFZ physical move it's weak to
cough cough Doublade. Because of this the only move MMX will reasonably run that beats you is special ghost (Moongeist Beam or Ghost Judgement). Because special ghost already hits Doublade, people will pair it with a fighting move (typically Close Combat) as it also allows you to hit darks in the same slot. Fire + Ghost would be unoptimal as you would have to dedicate an extra slot to darks (or just miss them), which is why you typically see fire with bug, or electric/grass on Photon Geyser less sets to hit either Ho-Oh or Mpert. You can take advantage of this, and pair FC Mbro with an SSap WG steel who answers the set without a Life Orb, and with a Life Orb can't switch into Photon but it's relatively easy to play around, or you can pair it with Prankster Celesteela or Zygarde-Complete. The most optimal combination would be Prankster SSap Celesteela + Fur Coat Slowbro-Mega, because not only does this answer essentially every 4 move MMX (and most band sets seeing as they typically run a fighting move), but Prankster Celesteela acts as both a Huge Power or No Guard Fissure Kartana check in one and also and answer to Suneteel/Geist/Fairy. I also think it's worth noting Doublade with a fire immune ability is very similar to FC Mbro in the MMX sets it checks, but due to it's ground weakness and lack of Scald/Water Shuriken STAB it is a much less relaible PDon check making it less optimal to run.
Instead of FC Mbro, you can also run STag. STag has its pros and cons. While yes it does serve as a PDon and MMX answer in one, you are kind of just fishing for them not to have Shed Shell. You also get Trick Scarf giving you a better match up into harvest but at the cost of losing utility. Running STag also means it takes more skill to play because you actually need the STag Pokémon infront of the thing you need to kill. I would reccomend this set (
https://pokepast.es/c73d241e37fc1435) for the most part but you can also run STag MMX with First Impression. This MMY allows you to kill multiple MMX rather then relying on a CFZ, and aswell STag is probablys one of the best answers to Choice Band MMX.
Kartana
Kartana is potentially the most influencing Pokémon for stall cores, and it has 2 sets you will need to answer. I'll make a list of every way you can answer both No Guard and Huge Power Kartana on stall.
-Prankster Celesteela
Prankster Celesteela is arguably the most optimal choice for a few reasons. It serves as an answer to MGeist MMX, Sunsteel/Geist/Fairy, and both Huge Power and Fissure Kartana. The main negatives of Prankster Celesteela are that you won't have an answer to Sheer Cold Kartana or Sunsteel/Electric/Fissure, but imo it's worth the draws. By running Prankster Celesteela it also means you can't run another Prankster user which you would typically want to use as a strong answer to special attackers, such as Ho-Oh, but cores without a Prankster Steel have their own issues too so I won't necessarily consider it a negative.
-Prankster Steelix-Mega/Aggron-Mega + Wonder Guard Steel
Having to answer Kartana in 2 slots is generally a negative because obviously that takes up more slots and it makesnit harder to play against multiple, outside of CFZs it doesn't actually do much over Celesteela in terms of hard answering anything on that list and Celesteela gets to answer Sunsteel/Geist/Fairy so imo Prank Celesteela is a better choice.
-Sturdy Heatran
Sturdy does 2 things for Heatran. First of all it means you don't just lose to Gastro Acid + Fissure, and second of all it let's you answer both Huge Power and No Guard Kartana in the same slot. Sturdy Heatran is the only way to answer both Kartana variants whilst serving as a "Wonder Guard". Main negatives I can think of are that despite being a Wonder Guard Steel, you don't answer MGeist MMX, and unlike Prankster Celesteela you don't answer Sunsteel/Geist/Fairy relaibley because of Protean MMY. Using Sturdy Heatran enables you to not run a Prankster steel however which is nice.
-Wonder Guard Steel + MBounce 4x steel resist
This method takes 2 slots which is generally a negative. Being forced to run a Wonder Guard steel means you dont exactly have a hard answer to MGeist MMX (though I don't think that's a huge drawback), but the main issues are you either have to run MBounce Magneton who has to hold an eviolite or Heatran who is wean to water meaning opposing Scald MBro are a concern and it is a sketch improof to your own. Both are also 4x ground weak which you may see as a negative for an MBouncer but personally I think it's fine as the only real thing running TWaves and hazards is MBounce Zygarde-Complete, who gets harrased by Shed Shell Imposter anyways.
PDon
As established earlier, you really should be running FC Mbro so this shouldn't be a huge concern. You may be saying "well pdon can tech for fc mbro in the form of something like freeze dry", which is correct, however by running Water Shuriken all set up PDon lose. Running Water Shuriken does have its drawbacks however, you can't really pressure Magic Bouncers at all if you are running hazards on Mbro and you also can't answer Shell Smash MMX. Defensive Magic Bouncers aren't that common nowadays from what I see and it's not like having Scald is going to necessarily win you a game against them anyways, plus this only applies if Mbro actually does have hazards. For Shell Smash MMX, I don't see it that much and it is possible they can run coverage for you regardless, but if you have another Pokémon on your team that can relaibley answer it then it shouldn't be a concern anyways. I think it's generally team dependent, and if your core is also already strong into PDon then Water Shuriken maybe less incentivisng, but overall I prefer Water Shuriken. There is one PDon set you will however not be able to answer with just FC Mbro, which is Choice Band Mold Breaker. Issue with it really is that the answers to it are quite limited, the 2 answers to it are Prankster Slowbro-Mega and Prankster Ho-Oh. Prankster Ho-Oh is fine (and probablys the best Prankster user for teams without a Prankster steel anyways), but Prankster Mbro shouldn't really be ran most of the time because it means you aren't running FC Mbro which means your Pdon and MMX answers are in 2 separate slots making running it less optimal. Choice Band Mold Breaker Pdon isn't very common at all seeing as it isn't great into offense in a very offense orientated meta and it is also very prediction reliant and can take time to break times so you can get away with not preparing for it. It's not an auto loss facing it anyways as after rocks chip it dies to Water Shuriken, they need to get multiple predictions right and Imposter is able to switch into it.
Just to point out I wrote all of that before I added the part to the MMX section about STag. With this set (
https://pokepast.es/c73d241e37fc1435) you want to click LTBTS on PDon if they haven't set up, and Water Shuriken if they have Shell Smashed, because Water Shuriken doesn't OHKO unless they Shell Smash. Also one of the better answers to Mold Breaker Choice Band PDon.
Harvest Slaking
Harvest Slaking isn't very common right now because as I have mentioned the meta is very offense orientated, but it is still worth preparing for and isn't terribly hard to prepare for either. All stall teams want a move that forces it out with the main ones being Taunt, Core Enforcer and Whirlwind/Roar. If you are running a Prankster Steel, just give it Taunt and that'll do. If you aren't running one, try slot Core Enforcer or Whirlwind/Roar on one of your sunsteel resists. A move that can force it out isn't enough however because it can just keep coming in and out to PP stall you, so you will want either TSpikes or if you're running STag then giving it Trick should do. TSpikes is generally enough unless they have Alolan-Muk in which case it could be a problem, but I wouldn't give it too much thought because Harvest Slaking is rarely seen now anyways.
MGeist Coverage Fishes
By MGeist coverage fishes, I mean sets that have Shell Smash and MGeist, with the other 2 moves being coverage for MGeist walls. There are a few ways I would reccomend going about this. First of all, just run 2 MGeist walls (either like Mbounce Yveltal or a Wonder Guard). It is not very likely they have both coverage moves that can actually hit both MGeist walls, especially considering if they do run 2 coverage moves like that they will get walled by any team with Zygarde-Complete. Meloetta at full tanks Bug Buzz from even Gengar-Mega and kills it back with Spectral Thief, and the only way Meloetta actually will take chip is if they can force hazards up through MBounce, in which chase chances are you're cooked anyways. You can also run a core like Arceus + Meloetta which should answer pretty much answer all MGeist coverage fish sets because running fighting and bug together is counter intuitive because you have 2 moves that hit dark. Secondly, if you aren't running a Prankster steel then you can just run something like Prankster Ho-Oh who answers all of these sets assuming they can't get rocks up. And finally, Sturdy Muk is a really solid MGeist answer because people will usuall rely on Fissure as their method of hitting Alolan-Muk rather then Earth Power which generally isn't worth using. One concern with Alolan-Muk however is that because you resist MGeist, Dawn Wings does like 80% with its CFZ to you at +2. It also means after like quite a bit of hazard chip Gengar-Mega can possibly break you but again if they can get hazards up through MBounce chances are you're cooked anyways.
Sunsteel/Geist/Fairy
Sunsteel/Geist/Fairy is essentially just a really broken 3 move set, which is usually ran by Protean MMY. I only really see Aerobee run it, but I still think it's worth prepping for and it's a very good set. Because Protean MMY is immune to SThief, walls to it are very limited. There are about 3 ways you can wall it. First is WG Bisharp, who doesn't do much else other then answer Protean MMY and is weak to Fissure so it's unviable on stall. Second is Prankster steels, I'm not sure on the calcs with Mlix but Prankster Celesteela walls it and if you are going to run a Prankster Steel that's the most viable choice anyways. Finally, Prankster Ho-Oh is able to wall it. While yes the answers are limited, at the very least cores with and without a Prank Steel can answer it.
No Guard MMY
It's a rare set you could probablys get away with not prepping for but I'll go over it anyways. There are 2 (or 3 I guess) variants of this set. First of all are the variants that run Sing, using the moves Sing/Photon/Zap Cannon/Fissure. The most obvious answer to this is Meloetta and Wonder Guard steels
might be fine but I haven't done the calcs. Second of all is the beat up variants which opt for Beat Up over Sing. Beat Up allows them to kill Innards and Meloetta in 1 slot, at the cost of missing WG steels, so obviously you answer it with a Wonder Guard steel. Finally there's variants that opt for Shell Smash over Beat Up or Sing, I've never see one but I suppose Meloetta or a WG steel with SThief would work. If you don't cover all of these I wouldn't worry because they are barely used.
General Special Photon
To be honest, I don't exactly know what special photon looks like. There's the Spore sets with MGeist and Photon, which you would just answer with a Safety Goggles Prankster Pokémon, a Wonder Guard that resists both moves (ideally with goggles) or MBounce Yveltal. I already went over No Guard, and I suppose they could also spam coverage picking between Steels, Muk, Yveltal, Zygarde, and Meloetta/Gyarados but I've never seen such a set and you would probably cover for it the similar to how you do with MGeist coverage fishing anyways. I have never really had issues with special Photon though and it isn't that good so it's fine.
No Guard TSpikes Taunt MGar
This is a more recent set but it's really good at forcing up TSpikes enabling teammates like Taunt WG Arceus, and in general if they are up you're not in a very good spot. The set on Akira's sample Clockup Flowers runs Taunt/TSpikes/MGeist/Fissure, and more recently Aerobee has been swapping out MGeist for Zap Cannon. Both sets are kind of answered by an MCoat MGeist resisting Wonder Guard, I say kind of because if the Wonder Guard isn't in on it you have to play a 50/50 on whether you go to an MBounce user or your Wonder Guard and then another 50/50 on whether you defog predicting them to switch out or click MCoat predicting them to Taunt, and the 50/50s aren't really in tour favour. MBounce Yveltal is the only Pokémon who can actually do something other then answer this set who answers the version on the sample, although if you want to answer borh the Zap Cannon variant and the MGeist one you have to run MBounce Zapdos. If you actually have the option to just slap whatever in your MBounce slot, I will say Zapdos is worth it over say Zygarde-Complete because Aerobee's teams are the best teams in the game.
WG Sweepers
There is exactly one good WG sweeper in the game, Taunt Arceus. Answering WG Taunt Arceus isn't too difficult, you need either Audino-Mega or Meloetta with Magic Coat, or you just run Audino-Mega and Meloetta and spam switch between them. TSpikes also denys it from coming in, and if you give a mon that can tank a hit from it Toxic you honestly should be fine. The others are Gyarados-Mega, Ash-Greninja and Hoopa-Unbound. If your team is good you already have an answer for Gyarados-Mega, for Ash-Greninja I honestly couldn't tell you but it is irrelevant anyways, and for Hoopa-Unbound that's even more irrelevant then Ash-Greninja and has the same walls except it drops to U-Turn so it's easier to answer. If you're running STag then First Impression kinda deals with these too.
Examples
Now that I have told you how you can optimally fit answers for everything, I will show you some examples of teams which do so. These teams cover about most of the game and their main issues are not being able to make good progress into defensive MBouncera and also anything that is able to force hazards up, which are more so issues with hard stall in general.
Click on sprites for team.
The amount this team covers is pretty insane. Prank Celesteela + FC Mbro is incredibly solid into the vast majority of MMX sets, with the only problamatic ones I can think of maybe being Shell Smash with a fire moves and Choice Band with Fire and Bug. Prank Celesteela is solid into most Kartana people use, because of Heatran people are pretty much always gonna opt for Fissure over Sheer Cold and I don't ever see Bolt Strike, Huge Power Kartana with a fire move could be a concern but that isn't really ran atm. PDon MU is incredibly sold, the only potentially problematic set being CB Mold Breaker which isn't ran and can be played around. Harvest Slaking MU is fine unless they have a TSpikes absorber but Harvest Slaking has fell off anyways due to how good offense is. MGeist MU is incredibly solid, Steela walls Sunsteel/Geist/Fairy and coverage fish sets can't cover for all of MAud, Meloetta and Prank Steela. Special Photon is fine? I'm not sure if people run Photon/Bug Buzz/Searing Shot but if they do I suppose that could be a concern. This team had the room to fit Zapdos so I ran it, which is just a blatant Aerobee CTeam but definitely worth it imo. WG sweepers are fine, WG Taunt Arc is answered by spam switching between both Wonder Guards, Gyara gets walled by Steela, and I'm not sure what Ash-Greninja or Hoopa-Unbound run and I don't care what Ash Greninja or Hoopa-Unbound run. Pretty solid team but issues are spam in general, things that can force hazards up through MBounce Zapdos (like Taunt/Spikes Mold Breaker Gyara or something) and opposing MBounce you can't make progress against but the stall vs stall MU is more or less a tie. Honestly wish I submitted this team instead of the Magneton one.
This is the team the most people will recognise because I submitted it as a sample. Prankster Ho-Oh essentially beats all special attackers that aren't Sheer Cold. Sheer Cold isn't ran over Fissure on special attackers really at all atm, and Meloetta should be fine for them. It walls Zap Cannon MMY regardless but the Wonder Guard Core deals with it if you are scared of para hacks. MMX MU is similar to the prior team except LO triple moldy MMX is slightly problematic as it can 2HKO Scizor with Photon on switch in, however it's definitely playable as the thing chips itself down over time plus isn't a common set due to the lack of priority. PDon is essentially solved. Kartana MU is arguably worse then the last team because the Kartana answers are spread out over 2 Pokémon meaning multiple Kartana could pose more of a threat. MCoat Meloetta allows it to answer Taunt WG Arceus, and provides more room to play around NG Taunt TSpikes MGar all though the MU isn't in your favour. Magneton not having an Eviolite means that STag Pdon is a concern especially considering how much this team hates rocks being up, and outside of that it has the same issues as the other team so I don't like this one as much.
This team opts for STag MMY instead of FC MBro meaning that Shed Shell MMX or PDon could be a concern, but the team has a better MU into CB MMX and Harvest Slaking mainly. Prankster Doublade is to not stack a fighting weakness with Ferrothorn who I ran over Scizor because I didn't need it to wall MGeist MMX. Meloetta and MBounce Yveltal is pretty good into MGeist and special Photon all though this team doesn't have an answer for Sunsteel/Geist/Fairy, Searing Shot Hoopa-Unbound or Ash-Greninja could also pose a threat. This team was made before WG Taunt Arceus really took off but MCoat Meloetta could probably be slotted in if needed. NG Taunt MGar MU is fine until it's Zap Cannon, to be fair MGar Zap Cannon does like 40% but chances are you get para haxed. Kartana MU is pretty similar to the prior team. Rest of the issues are the same as the other teams really (general stall issues), all though Knock Off Yveltal means Shed Shell Imposter isn't a concern.
Conclusion
Hopefully by now you agree that stall is an actually good archetype, because common opinion is that it isn't that good. I have also hopefully proved defensive counterplay is real on stall, but for balance I couldn't say the same thing. Balance isn't able to stack checks to things like stall can (e.g. Kartana checks) and also struggles to fit things like Fur Coats so balance defensive cores end up being a lot worse, and balance also isn't really going to be out offensing good offense. As well from playing against balance with stall they're also pretty easy to wall and they can't make progress into MBounce. The prevelance of spam hurts, but semistalls with Mold Breaker Pokémon that set hazards and remove items plus a perish trap Pokémon or Harvest Slaking semistalls are not that common which is good for stall. Overall, I actually think stall is more consistent then balance now, and thus a better archetype. I'll probably get flamed for this opinion, all though atleast Aerobee agrees with me. Thank you for reading, goodbye.