"Strong Pokémon. Weak Pokémon. That is only the selfish perception of people. Truly skilled Trainers should try to win with the Pokémon they love best."
-- The Fourth Johto Elite Four, Karen
Which, sadly, doesn't work all that well in metagame.
One of the reason reasons I don't dedicate too much to metagaming. Although it can be fun and rewarding.
That picture I posted earlier was of my team of NU (Never Used) Pokemon, plus Quagsire. (From RU, or Rarely Used.) I was fighting in the Ubers tier, and I won. I win about 1/3 to 1/2 of my matches with that team in Ubers, which isn't a
great ratio, but I enjoy using weaker Pokemon to their best potential. Quagsire with Water Absorb completely shuts down Kyogre, who is otherwise bar-none the most powerful Pokemon in the game. Quagsire with Unaware doesn't give a fuck about your Calm Mind Deoxys or your Swords Dance Arceus. It laughs in the face of Speed Boost Blaziken. Its weakness?
Grass. Particularly Ferrothorn. So I have a Miltank with Sap Sipper. Switch into the inevitable grass move, power up attack, return the favor with Fire Punch. As far as defenses go, Miltank is not Blissey. But with Milk Drink, passable defenses, and Heal Bell, it's hard to outstall. I've outstalled a Giratina with that bad motherfucker. My revenge killer and occasional lead on that team is John Kreese the Sawk. (He follows the ideology of '
Strike first,
strike hard,
no mercy!) No form of Kyurem can stop his Close Combat. No form of Deoxys can survive his Payback without a focus sash. (Since with Sturdy, he
will survive their first Psychic attack.) Ninjask is mainly for boosting my other Pokemon, but can pack a surprising punch with X-scissor. Enemy psychic types often expect me to just stall for speed and wind up with a face full of pain. Relicanth is for breaking walls. Head Smash is powerful enough to 2HKO a Groudon without boosts. He is only let down by his speed. Hence the Ninjask. Swellow is for sweeping without boosting. Guts plus a toxic orb, Brave Bird and Facade will take out just about anything that doesn't resist them both. And even then, he'll do some damage. U-turn can give me some momentum. (Instantly swapping Quagsire in to take a hit from Kyogre, swapping in Quagsire to take a hit from Zekrom, swapping in Quagsire to take a hit from Heatran...)
They are not more powerful Pokemon, but their movesets and IVs are tailored very specifically to function in Ubers. They have just enough speed IVs to outspeed the Pokemon they need to, so that the rest can be put into either attack or defense, depending on their role. It requires a lot of specialization, so naturally this team doesn't work very well in RU.
A for EV training, I haven't done it with very many Pokemon in-game. Just my Bullet Punch Scizor, my Subpunch Breloom, my Ultimate Critical Absol, and my End of All Things (Scarf) Kyogre. I didn't bother getting 31's across the board, so Breloom and Absol have random stats. Kyogre was savescummed a bit until his speed was at least 25. Scizor wasn't bred for IVs, but somehow wound up with everything at least 25. (And 31s in attack and speed, which are just about the only stats that matter for him anyhow.)