Newest viability rankings
Tyranitar is one of the most definitive Pokemon in BW OU thanks to it setting sand and keeping dangerous Psychic-types like Latios, Reuniclus, and Alakazam in check by Pursuit trapping them. Sand is a key component of the metagame, since it keeps rain off the field, limiting dangerous Pokemon on rain teams like Thundurus-T and Tentacruel, and works very well alongside other means of residual damage, like entry hazards and status. Sand damage puts Pokemon like Keldeo, Latios, Rotom-W, and Starmie on a timer and negates Leftovers recovery for many others. Outside of Psychic-types, Tyranitar also checks common threats like Thundurus-T, Heatran, Jellicent, and Volcarona if running Tanga Berry, and it can revenge kill and Pursuit trap faster threats with a Choice Scarf set. Tyranitar can even run lure options for checks like Skarmory, Excadrill, and Gliscor thanks to its deep movepool.
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Latios is one of, if not the, best wallbreakers in the metagame thanks to its insanely strong, nearly unresisted STAB Draco Meteor. This makes sets utilizing Choice Specs very difficult to switch into, let alone wall. This is further compounded by Trick crippling almost every defensive answer. It also has a great Speed tier that allows it to outspeed prominent threats like Keldeo, Terrakion, and Garchomp. This makes it a great Choice Scarf user, as it can outspeed all other Choice Scarf users and boosted sweepers. Latios's decent bulk and typing let it check Pokemon like Keldeo, Thundurus-T, Breloom, and Gliscor relatively well, which is made even easier due to its immunity to Spikes. It can even run Recover to aid its ability to check these Pokemon and mitigate sand and Stealth Rock damage. It's also great on rain teams, where it can hit most Steel-types hard with boosted Surf. Latios can also work on sand teams thanks to sand damage wearing down some of its counters and its ability to check and remove many Pokemon that pressure sand teams well, namely Breloom, Heatran, and Gliscor.
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There is no Pokemon in BW OU with the same effectiveness as a supporter as Ferrothorn. With a great defensive typing, good stats, and a fantastic support movepool that includes Spikes, Stealth Rock, and Knock Off, it is an invaluable addition to offensive and defensive teams alike. The ability to absorb powerful hits from and check Dragon-type attackers like Latios, Kyurem-B, Dragonite, and Salamence gives Ferrothorn many opportunities to switch in, as does its ability to take powerful Water-type attacks like Hydro Pump from Choice Specs Keldeo and Starmie. Once in, it can set entry hazards, remove the foe's item, or use either of its two powerful STAB moves.
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