First and foremost, I'd like to thank Gary and bludz for running the Generation 7 OU Viability Rankings before I ultimately took it over during 2018. It is one of the most viewed threads on the forums and it serves as a major resource to thousands of players, both new and experienced. Personally, I have taken great pride in being able to contribute to the OU VR as much as I have, even if it has not been as much in recent months as I would have liked it to be. I do plan to continue running the thread moving forward into Generation 8, too!
I would also like to thank everyone who was on the OU Viability Rankings Council -- we have had well over a dozen members over the course of the generation, but we currently have ABR Lopunny Kicks talah suapah and myself. I hope that the VR Council next generation is as informed and efficient as it was this generation; it makes the OU subforum as a whole a much better place and helps the entire playerbase learn about the metagame in a plethora of different ways specific to the conclusions we individually draw on what is rising, falling, etc.
After the slate, which will come in the following post, I intend to keep this thread locked and someone will probably start a new thread in the Ruins of Alph subforum once Generation 8 starts and some of the dust settles here in coming weeks. For the time being, consider this my thank you to everyone who contributed to this thread through posting, to everyone who contributed to the entire subforum through posting or discussing ideas with me personally, to everyone who viewed these threads -- even if it was solely for your own benefit as we largely do this for you after all, and to all of my fellow moderators ( Colonel M Leo TPP Jordy GMars Indigo Plateau ) and contributors over the course of the generation. I am very happy that my transition to OU Forum Leader went as smooth as it did and I am even happier with the state of this subforum. I hope that Generation 8 brings even bigger and better things!
I would also like to thank everyone who was on the OU Viability Rankings Council -- we have had well over a dozen members over the course of the generation, but we currently have ABR Lopunny Kicks talah suapah and myself. I hope that the VR Council next generation is as informed and efficient as it was this generation; it makes the OU subforum as a whole a much better place and helps the entire playerbase learn about the metagame in a plethora of different ways specific to the conclusions we individually draw on what is rising, falling, etc.
After the slate, which will come in the following post, I intend to keep this thread locked and someone will probably start a new thread in the Ruins of Alph subforum once Generation 8 starts and some of the dust settles here in coming weeks. For the time being, consider this my thank you to everyone who contributed to this thread through posting, to everyone who contributed to the entire subforum through posting or discussing ideas with me personally, to everyone who viewed these threads -- even if it was solely for your own benefit as we largely do this for you after all, and to all of my fellow moderators ( Colonel M Leo TPP Jordy GMars Indigo Plateau ) and contributors over the course of the generation. I am very happy that my transition to OU Forum Leader went as smooth as it did and I am even happier with the state of this subforum. I hope that Generation 8 brings even bigger and better things!
from A to A+: Gliscor has seen a lot of usage in recent months, dating back to the start of Smogon Snake Draft. The Swords Dance and Stealth Rock variants both play a large role in the current metagame and it stood out in the A tier that it previosuly resided in. While it may be one of the weaker members of A+, Gliscor still is a nasty win condition, almost always winning against unprepared teams, and a superb Stealth Rock setter with plenty of utility such as sponging status, checking potent threats like Heatran, and abusing Toxapex, which only a few other Pokemon can claim to do. 
from A to A+: Yes, this is Mega Latias, for those confused by the sprite. Regardless, Mega Latias has always been a pesky presence in the metagame, but recently the Calm Mind variants have hit unprecedented levels and the utility variants offer a lot to specific balance structures, too. Given this and increased overall usage, it should be no surprise to see Mega Latias rise to A+ to close out the generation.
from A- to A: Yes, this is Mega Latios, for those confused by the sprite. Regardless, Mega Latios has cemented itself as a potent mixed attacker, posing a threat to entire teams oftentimes and even having a decent defensive niche, checking some Kartana, Heatran, and Rotom-Wash. All things considered, Mega Latios has been good for a couple of years now and lately it has seen more usage alongside Magnezone as well as on balance teams that want a bit more of a punisher that provides some defensive utility, so it is unsurprising that Mega Latios is back to A and on a slight rise. 
from A- to A: Clefable is nowhere near as good as it once was in ORAS OU, but it is still a respectable option, setting up Stealth Rock effectively and providing massive amounts of utility through various moves it learns. On top of this, it can double as a dangerous Calm Mind sweeper if that fits your team composition. Clefable probably should have been A for a while if it was just up to me, but recent balance builds have given it more usage and this was likely reflected in the vote as a whole, finally getting it back up to A.
from A- to A: Mega Lopunny is a great anti-offensive measure, giving you strong attacks from two respectable STAB typings and a lot of speed. This also is coupled with priority from Fake Out and even sometimes Quick Attack, which lets it function as a revenge killer and a breaker against bulky-offensive teams. In some match-ups, Mega Lopunny can just take over and this potential is too high to leave it in A-. 
from B+ to A-: Kyurem-Black has been a strong Pokemon all generation, but recently more people have been taking advantage of it as a balanced core breaker, specifically with the Z Freeze Shock set seeing consistent usage. It takes some decent timing, but Kyurem-Black can be a kill machine against the right type of build and we see a lot of these right now, so it should be no surprise that it is gaining some traction.
from B+ to A-: Finally, the Grass snake Generation 5 starter is back to the A ranks, finding itself a spot in A- to end the generation. While Serperior is sometimes inconsistent, Substitute variants have been great as of late and moves like Glare and Leech seed present so much utility that abusing Contrary Leaf Storm is oftentimes worthwhile. 
from B to B+
from B to B+
from B to B+
from B- to B+
from B- to B+
from B- to B
from C+ to B-
from C+ to B-
from C to C+
from C- to C+
from UR to C
from UR to C-
from S to A+: While Ash Greninja has been and will remain a potent force within the metagame, there is still a fair amount of counterplay to it and the amount of Defoggers going around makes the offensive Spiker aspect of it a bit less appealing at this exact moment in time. For me, this was a fringe S pick still, but Ash Greninja has seen better days and is not as metagame defining as it once was, oftentimes being overshadowed by more flashy threats on teams it previously always fit onto. Perhaps the lack of defensive presence got to it or perhaps people finally prepared sufficiently for it, but regardless Ash Greninja is still sitting pretty in A+, which is a respectable placement for it.
from A+ to A: Over the last 6 or so months, Mega Alakazam has slowly dropped in viability and now it is finally reflected in its subrank dropping a little. While Mega Alakazam is still superb, it is not as potent as it once was and the amount of usage it has seen has dropped significantly. 
from A+ to A: Z Garchomp is no longer the best Stealth Rock setter in the tier and while it still has a big niche, hence the A ranking, it is not really taking advantage of the great role compression that Garchomp once brought teams -- Gliscor is a good Stealth Rock setter that checks Heatran, a lot more Ice moves are floating around due to Gliscor rising in usage, and teams prefer more durable options like Clefable and Ferrothorn oftentimes, too. 
from A to A-: The match-up moth finally ran into a few too many poor match-ups for people's liking, I suppose.
from B to B-
from B to B-
from B to B-
from B to B-
from B to B-
from B- to C+
from C+ to C
from C+ to C
from C- to UR
from C- to UR
from C- to UR
