Like it was in past generations, extending weather from 5 to 8 turns is oppressive for most teams to deal with in SS Monotype. So, in what should be no surprise, the council has voted unanimously to once again ban both Damp Rock and Smooth Rock from Monotype.
In Smooth Rock's case, it smooths over Hippowdon's lack of pivoting options and means Excadrill is not pressured to switch into attacks at all because it has more than enough time to eventually find its way into play. In addition, once it is in play, Excadrill has far too many turns of sand to sweep or set up against the opponent. In fact, Excadrill can happily switch out and sometimes switch back in before sand has to be reset by Hippowdon. Given how much momentum is lost by Hippowdon, this is a huge win for Ground teams against offense. The combined effect of both alleviating pressure put on the sand team by removing the onus to take risks to get Excadrill in quickly along with applying significantly more pressure on the opponent by giving Excadrill more turns to sweep means Smooth Rock is currently too good for Monotype.
For Damp Rock, Swift Swim sweepers are arguably better than ever. Barraskewda has fantastic coverage and is extremely fast even outside of rain, giving rain even more consistency than before and patching up the loss of Greninja's revenge killing. Seismitoad is still running around firing off ridiculously powerful Hydro Pumps, pairing extremely nicely with Barraskewda, and it even gets Stealth Rock, which you have much more time to set up when you have 8 turns of rain instead of 5. It isn't just Swift Swim sweepers that make Damp Rock too good, though. The great 1.5x damage boost to Water-type moves during such an extended period turns many Pokemon into wallbreakers. One great example is Dracovish, whose Fishious Rend goes from 85 BP to 170 BP when going first to 255 due to STAB to 382.5 in rain to 573.75 with Strong Jaw. When combining the effectiveness of Swift Swim sweepers and rain-boosted attacks, 8 turns is simply too long in Monotype.
In an offense-dominated metagame, extended weather is simply too restricting on teambuilding and is far too punishing. For these reasons, Damp Rock and Smooth Rock are now banned. You are welcome (and encouraged!) to discuss this ban and the effect it will have on the metagame in the metagame discussion thread.
Tagging The Immortal to implement. Thank you!