This guide is specifically on the Training for EV's, there are now links to lists of the pokemon and what EV they give, and where they are located in the guide. Please leave any questions, comments, concerns, complaints, or compliments
Explanations of EV’s:
When your pokemon defeats other pokemon, not only does it gain experience points from them, but they also gain another kind of point called EV (Effor Values). There are 6 kinds of EV's, one for each stat: HP, Attack, Defense, Sp. Attack, Sp. Defense, and Speed. Each kind of pokemon you defeat will give you a certain number of EV's for a certain stat.
An example would be defeating a rattata gives you 1 EV in Speed while defeating a gengar gives you 3 EV's in Sp. Attack.
A list of all the pokemon and what EV's they give you can be found on bulbapedia here
When you gain 4 EV’s for a certain stat, that will give you an extra overall stat point when your pokemon reaches level 100.
Example: Lets say a pikachu with 0 EV's in speed at level 100 will have a speed stat of 200. So a pikachu with 4 EV's in speed at level 100 will then have 201 speed.
Limitations of EV’s:
However, there is a limit to how many EV’s your pokemon can gain. You can gain a maximum of 255 EV points in a single stat, and 510 EV points overall. However, because 255 is not divisible by 4, it is more logical to give it a maximum of only 252 EV’s instead, since it’s the next highest number divisible by 4.
So this translates to a maximum of 63 extra stat points in a single stat when your pokemon reaches level 100. And by giving only 252 instead of 255 in a stat, this allows to max out 2 stats of their EV points, and leave 6 possible EV's left over for another stat. However, you don't have to choose 2 stats and max their EV's, the spread of the EV's you choose can vary widely, so many people put a certain number of EV's in certain stats depending on their strategy.
Other methods of gaining EV’s include using those expensive vitamins. How those vitamins work is that they give your pokemon 10 EV points in the stats they increase. Your pokemon can only take up to 10 of each kind of vitamin, so you can gain a maximum of 100 EV’s in each stat from vitamins. The vitamins are:
HP Up: HP
Calcium: Special Attack
Zinc: Special Defense
However, when you use vitamins, the EV's they give you can't exceed the first 100 EV's of your pokemon's stats. So for example, if I gained 50 EV's in speed from battling, then I would only be able to use 5 Carbos because I can only use that many before my speed EV's exceed 100.
Other Methods and Hold Items:
Also, any pokemon who gains experience from the killed pokemon, will gain the EV’s from them. Which means, you can enter a fight with one pokemon, switch it out, kill it with another pokemon, and the first pokemon you entered the battle with would gain the EV’s as well, because it gained experience from the killed pokemon..
That method also includes pokemon holding the exp. share, this way, the pokemon holding it does not even have to enter battle to gain the EV’s.
There are also ways you can gain EV’s more efficiently. One is using several kinds of hold items. First, there is the macho brace, which you get from Pastoria City. When your pokemon holds this, the EV points they gain from battling are doubled. So killing a rattata while holding the macho brace would give you 2 EV points in speed instead of 1.
There are also other items your pokemon can hold to gain EV’s effectively. I actually suggest these over the macho brace. What these items do is they add an extra 4 EV’s of a certain stat to the EV points you gain from battle. These items are:
Power Anklet: +4 EV speed
Power Band: +4 EV sp. def
Power Belt: +4 EV def
Power Bracer: +4 EV attack
Power Lens: +4 EV sp. Attack
Power Weight: +4 EV HP
You gain these items from the point exchange place at the battle tower. So if you fight a rattata while holding the Power Anklet, you will gain 5 EV points for speed when you defeat it instead of 1. Or, if you fight the rattata while holding the power weight, you will gain 1 EV point for speed, and 4 EV points for HP.
One last method is that your pokemon can randomly contract a virus called Pokerus. The lady at the pokemon center will tell you if any of your pokemon in your party has pokerus and there will be a little purple box on the bottom right of its picture. When your pokemon contracts it, all the EV points it gains from battle will be doubled for now on. And the best thing about pokerus is, is that it is contagious. You can spread it to other pokemon in your party just by battling, and eventually, your other pokemon will have the virus as well.
However, there is a limited amount of time you have for your pokemon to spread the virus. When that time is up, a little smiley face will appear on the lower right of its picture, and it will no longer be able to spread it, but it will still gain double amount of EV’s from battle. You could technically stop time for the virus, by keeping it inside a storage box. It won’t be able to spread the virus, but the time limit won’t expend when it is in there.
There are also ways to reduce the number of EV’s you have. This is useful incase you accidentally gained the wrong kind of EV’s or something. They are all berries, and they reduce the EV by 10 points when you use them on the pokemon. They are:
Hit Point EV: Pomeg Berry
Attack EV: Kelpsy Berry
Defense EV: Qualot Berry
Sp. Attack EV: Hondew berry
Sp. Defense EV: Grepa berry
Speed EV: Tamato Berry.
Which pokemon gives what EV's?
I'm working on this section, but there are a bunch of guides out there that tell you what EV's each poke gives you
Controversy of rare candies and day care:
Many people think that using either of those 2 methods would be bad for your pokemon. Which really is not necessarily true. The only reason you may see not as much stat growth from these methods is because they don't give you any EV's. So as long as you have gained, or going to gain, your maximum amount of EV's, there is no harm to level them using these methods. It's actually what I do in fact.
Confusion about EV’s:
There are many pieces of information many people get confused on regarding EV’s. Some people say that when you gain EV’s, you will gain all the extra stat points you earned the next time you level up, this is not true.
This may seem so because if you start EV training, you may see a significantly larger increase of the stat you are training in, when you level up. It all really depends on what level your pokemon was when it started EV’s training. When you EV train, the leveling up system tries to spread the extra stat points you earn, throughout all the 100 levels.
So if you started EV training when your pokemon is level 1, and even if you somehow gain all 510 EV’s before it levels up to level 2, you would not notice any significant increase in stats because the leveling up system spreads all of those extra stat points you earned throughout the leveling process.
However, if you instead started gaining EV’s when your pokemon is level 50, you would notice a significant increase in stats, because the leveling up systems would then give you all of those extra stats points you would have earned up until now, if you had gained those EV’s in earlier levels.
Some people have also asked me how many EV's they would get if they had pokerus while holding the items. Well, first, you calculate the number of EV's you get from the items alone, then pokerus would double it all. So for examle, if you were holding a power anklet, and killed a rattata, you would gain 5 speed EV points, then pokerus would double it, and so that would then give you a total of 10 EV speed points for killing one rattata.
Don't copy and paste this guide anywhere! But you can still link if you want.