I was looking at the teambuilder on Pokemon Showdown and noticed that a lot of Pokemon that were in OU were now "OU by technicality". I've only heard of OU by technicality in terms of megas, like Garchomp and Tyranitar, whose base forms were OU but mega forms didn't have enough usage in OU. However, I've never seen regular Pokemon like Electivire or Tentacruel in that limbo. I heard that past generation tiers had recently become unlocked, and that might explain why bad OU Pokemon like Electivire and Dusknoir are in there, but a lot of great OU Pokemon, like Jolteon, Shaymin, and Snorlax are in that tier, so I'm confused on what that tier is supposed to be.
| 37 | Hippowdon | 3.155% | | 38 | Milotic | 3.023% | | 39 | Aerodactyl | 2.892% | | 40 | Weavile | 2.784% | | 41 | Raikou | 2.730% | | 42 | Abomasnow | 2.321% | | 43 | Tentacruel | 2.200% | | 44 | Shaymin | 2.007% | | 45 | Donphan | 1.681% | | 46 | Heracross | 1.656% | | 47 | Snorlax | 1.566% | | 48 | Rotom-Mow | 1.554% | | 49 | Electivire | 1.495% | | 50 | Vaporeon | 1.476% | | 51 | Togekiss | 1.341% | | 52 | Dusknoir | 1.188% | | 53 | Jolteon | 1.113% |
source The problem is that Jolteon, Snorlax, and Shaymin are not great OU Pokemon right now.
These Pokemon historically, were good, however, their usage dropped off a cliff. However, since the formats are less played, they are actually technically UU or UUBL by usage, but they don't classify based off of usage nowadays.