Before I get into specifics, I believe that offensive boosting is an especially important part of this CAP. While on paper it's difficult to find resistances to both Ground on Rock, in practice the metagame is particularly unkind to EdgeQuake coverage, with the likes of Landorus-T, Ferrothorn, and Slowbro coming in easily. As such, offensive boosting is a great tool for CAP31 to be able to exert offensive pressure against these mons without relying on an oversized base Attack stat or a damage-boosting item.
While a plethora of other options have been discussed that allow CAP31 to still be useful against these switch-ins, I find boosting to be the most compelling due to its synergy with Diamond Storm. As others have already discussed, boosting allows us to leverage our +2 boosts particularly well by enabling us to gain more value off of avoiding revenge kills. Speed boosting has the added bonus of letting us strike first with Diamond Storm to proc a +2 boost before getting hit.
Now for specific moves:
Swords Dance has fantastic synergy here, and will undoubtedly be useful for CAP31, but it's not my personal favorite for a few reasons. I would argue Swords Dance is much more volatile compared to Dragon Dance and Shift Gear; Swords Dance offers far greater immediate power at + 2, whereas a number of pokemon can likely switch in on a +1 Attack CAP31. I feel like Swords Dance funnels CAP31 into a wallbreaker role, at least to some extent, which while certainly a viable option, is not necessarily desirable.
Shift Gear is certainly interesting, but I don't see it being much different from Dragon Dance in practice, as any variation between +1 and +2 Speed can alternatively be accommodated in the stats stage. I don't see the benefits of +2 over +1 Speed being significant enough to justify building around Shift Gear over Dragon Dance, so I'd rather just look at Dragon Dance instead.
Dragon Dance: Dragon Dance is probably my favorite option here. It's far less volatile than Swords Dance, as Lando-T and Ferrothorn are likely safe switch-ins to a +1 CAP31. Swords Dance has more immediate power over Dragon Dance, not only in a literal sense, but also because Dragon Dance primarily becomes useful in the late game when Lando-T and Ferrothorn have sustained enough chip. As such, there's a lot more room for CAP31 to operate- it can function as a bulky wincon fulfilling a primarily defensive role in the early game, or still lean into an offensive game plan. Even though a +1 Attack boost isn't likely to make immediate progress against opposing threats, I find the ability to boost to be especially important, specifically because it prevents Lando-T from pivoting in and out on us. Similarly, boosting speed is great for us as mentioned before, and gives us more breathing room for our base speed in the stats stage.
All things considered, I think all three of these moves should be included as optional defining moves, with Dragon Dance being my personal preference of the three. So yeah. Also Power-Up-Punch is a bad move
While a plethora of other options have been discussed that allow CAP31 to still be useful against these switch-ins, I find boosting to be the most compelling due to its synergy with Diamond Storm. As others have already discussed, boosting allows us to leverage our +2 boosts particularly well by enabling us to gain more value off of avoiding revenge kills. Speed boosting has the added bonus of letting us strike first with Diamond Storm to proc a +2 boost before getting hit.
Now for specific moves:
Swords Dance has fantastic synergy here, and will undoubtedly be useful for CAP31, but it's not my personal favorite for a few reasons. I would argue Swords Dance is much more volatile compared to Dragon Dance and Shift Gear; Swords Dance offers far greater immediate power at + 2, whereas a number of pokemon can likely switch in on a +1 Attack CAP31. I feel like Swords Dance funnels CAP31 into a wallbreaker role, at least to some extent, which while certainly a viable option, is not necessarily desirable.
Shift Gear is certainly interesting, but I don't see it being much different from Dragon Dance in practice, as any variation between +1 and +2 Speed can alternatively be accommodated in the stats stage. I don't see the benefits of +2 over +1 Speed being significant enough to justify building around Shift Gear over Dragon Dance, so I'd rather just look at Dragon Dance instead.
Dragon Dance: Dragon Dance is probably my favorite option here. It's far less volatile than Swords Dance, as Lando-T and Ferrothorn are likely safe switch-ins to a +1 CAP31. Swords Dance has more immediate power over Dragon Dance, not only in a literal sense, but also because Dragon Dance primarily becomes useful in the late game when Lando-T and Ferrothorn have sustained enough chip. As such, there's a lot more room for CAP31 to operate- it can function as a bulky wincon fulfilling a primarily defensive role in the early game, or still lean into an offensive game plan. Even though a +1 Attack boost isn't likely to make immediate progress against opposing threats, I find the ability to boost to be especially important, specifically because it prevents Lando-T from pivoting in and out on us. Similarly, boosting speed is great for us as mentioned before, and gives us more breathing room for our base speed in the stats stage.
All things considered, I think all three of these moves should be included as optional defining moves, with Dragon Dance being my personal preference of the three. So yeah. Also Power-Up-Punch is a bad move