Okay so I decided to take a look at the usage stats for January and found this.
I believe that Assist should be banned, not Groudon-P or Thousand Arrows. Groudon-P can be controlled to an extent, but certainly not the extent that Assistspam effectively has. The same deal for Thousand Arrows, it's good because it has no immunities but simply lacks in power with only 90 BP and no other benefits in most scenarios. I'd like to point out that my team-usage data is coming from various points on the ladder, but moveset data is purely based on the highest point that the stats cover (1760+), due to the fact that assistspam teams can get to the top of the ladder exceptionally quickly, and very reliably (There's an RMT that had 33-0 when it was posted using assistspam). Now let's take a look at some stats, because hearing me rant and reading statistics is fun.
First, let's take a look at the Groudon-P usage for each bracket.
All of Ladder: 3 | Groudon-Primal | 26.36691% |
Okay, so Groudon-Primal is used on a quarter of all teams, and is trumped by Rayquaza-Mega and Shed (that order). Pretty standard, exactly what we'd expect from a powerhouse such as him, even though it seems a bit high. Let's keep going.
1500+: 2 | Groudon-Primal | 33.96361% |
So Groudon-Primal moved up a rank, moving past shed by a small margin (less than 1%). Clearly this thing is better than we thought. Let's go deeper.
1630+: 2 | Groudon-Primal | 50.48627% |
Same rank, but look at the difference in percents. Now it's used on a bit more than half of all teams. Rayquaza-Mega's usage at this time is
52.96090%. Yeah, this is kinda getting close. But it can't possibly be used this much on 1760+ teams right?
1760+: 1 | Groudon-Primal | 70.72991% |
Yup. Groudon-P is the most-used Pokemon on all top-rank BH teams, trumping M-Ray by a full 12% (Ray-M's is 58.31896%). Well, this thing's obviously powerful, but why? Surely there must be some correlation between this and assist for me to be typing this post, or else I'd look dumb! Well, let's take a look at its moveset data.
Within the 1760+ moveset data, we immediately see that Prankster is the most used ability, trumping even Tinted Lens, its most powerful nuking set, by around 8% usage (27.188% versus 15.344%). Tinted Lens is also run on Assistspam teams to get around Ground resists, just so you know. Mold Breaker is the 3rd most used, which is also run on Assistspam to get around Fur Coat abusers and Sturdinja. Coincidence? The 4th most used ability is Magic Bounce, which is rarer on Assistspam but is still run. So what does this mean? Let's find out. Its most used item is Choice Band, trumping the second-most used Choice Scarf by more than 30% (43.798% versus 12.174%). Okay, they're obviously running it for the power with STAB V-create, or maybe because they're boosting Thousand Arrows up more. The spreads? All Bulky Physical Sweepers; 14.433% run 248/252, and the second most used 252/252 has only 5% usage. There's also a 236/252 set (the 3rd-most used one) with 20 speed, most likely designed to speed creep opposing Assistspam. So it's quite obvious by this point I wrote up this giant wall for nothing, Choice Band is obviously for V-Create and Thousand Arrows, etc. But what if I told you that I didn't just write up this wall for keks? What if I told you that the next paragraph is where I prove that Assist is broken?
Let's take a look at moves now, to show how overcentralizing Assistspam is on high ladder. The most used move on Groudon-P on high ladder, in of itself, is Assist, with a whopping 48.329% usage. Thousand Arrows, the move that most likely deserves to be the most used outside of V-create, is less used than Assist by ~15% (34.295% usage). Then again, this is also run on some Assist-scum Groudon-P. Now here's where Assistspam proves itself. I refer you to the 3rd most used move, not V-create, but Dragon Tail. Yes, that's right, Dragon Tail. Why would you run Dragon Tail on an Adamant Groudon-P? Because it's immune to Assist calling it. The 4th-most used move is V-create. Only the 4th. And now, the true proof. The 5th-most used move? FOCUS PUNCH. Yes, your eyes do not decieve you, FOCUS PUNCH. This is only used less than V-create by 1 single % (23.063 compared to 24.620). I could go on to talk about the 6th and 7th-most used moves (Trick and Switcheroo), as well as the fact that Thief is even existent on there, but I think I got my point across with FOCUS PUNCH.
But just one more thing that will really put the nail in the assist isn't OP coffin, since Blissey appears to be a partner to Groudon-P in its assist spamming efforts: Blissey's 2 most used moves, Thousand Arrows (59.937%) and Nothing (38.397%). Need I say more? I'm pretty sure I don't. Plus, who else is using Assist anyway? Banning it would have no negative consequences since nobody else is running it really outside of gimmicks.
tl;dr: Ban Assist. At the very least, ban the combination of Assist + Groudon-P, since Assist + Garchomp can be dealt with due to Garchomp's lesser bulk and worse typing in this meta (and 10 less attack).