Trust me, nerds really do enjoy this. Welcome to level eight.
A level eight trainer will utilize EV training. This is the most in-depth and mathematical portion of a trainer's Pokémon. this step requires vast knowledge of EVs themselves, Pokémon's EV yields, the locations of Pokémon with the best and most appropriate yields, and an even more severe understanding of Pokémon's stats. This level may contradict some of what was learned in level five.
Working out is a choice, just not for Pokémon. EV training is sort of like a workout plan for Pokémon, carefully formulated to get highly particular results. As stated in level five, there is a limit to how many total EVs that can be contributed to a Pokémon's stats. There is also a limit to how many of this total can go into any individual stat. To wit: a Pokémon can maintain a total of 510 EVs. Out of these, any stat can hold up to 252 EVs. For the most part, competitive trainers train two stats to the maximum of 252, and then dump the last six into another stat. For example, when training a Fast, Physical Sweeper, a trainer would put 252 EVs into Attack, 252 into Speed, and the put the last six into either HP, Defense, or Special Defense. Who knows? It might help it survive a hit... Maybe. Or when training a Mixed Wall with good Defense and Special Defense, 252 would be put into each Defense, and six would go to HP.
So how does one go about training a Pokémon like this? Using the EV Yields of opposing Pokémon, a trainer can mold their Pokémon's EVs any way they want. Using items like the Macho Brace or Power items will increase EV Yields. The hard part is figuring out exactly which Pokémon and how many to fight in order to get the desired result. This process can be further expedited with the use of the rare condition, Pokérus.
Pokérus, or The Pokémon Virus, is the rarest occurrence in the Pokémon world. Only one in over ten thousand wild Pokémon will be found with it. The upside is that it spreads rapidly. Pokérus' effects will only last a couple of days before wearing off, but even after it's gone, its carrier can still spread it. It has no negative effects, and its positive effects are substantial. A Pokémon with Pokérus will receive double the EVs when defeating a Pokémon.
Yeah, you can do all that, or... The sixth generation games, Pokémon X and Y, introduced the revolutionary Super Training. Super Training is a way simulate Pokémon for the trainee to take down. Doing so rewards the victor no experience, but EVs. Often times, the Yield of the simulated Pokémon is much higher than the Yield would be if the trainer took down a regular Pokémon. Super Training also utilizes punching bags with EV Yields. This process is many times easier than regular EV training, but X and Y added a different aspect that makes it easier as well. The implementation of Hoard Battles makes it possible to take down five of the same wild Pokémon at once. This essentially allows for five times the EV Yield, which can be much faster than Super Training.
Yes, in contrast to level five, this level encourages the fighting of limited opponents. This level also encourages the use of Rare Candies, as a fully EV trained Pokémon would receive no liability for it.