Training

Base Stats - IVs - EVs - Natures - Breeding

The following information is valid for the Third and Fourth generations.

Individual Values

When you "roll" a character in a tabletop game, you randomly generate values for your various statistics. Your Strength, say, will be a value between 3 and 18. Modifiers and bonuses are applied to them to get the stats you're going to use, but these numbers exist as a base. When you encounter a wild Pokémon, its stats are rolled in a similar way, only the range is from 0 to 31. There are six of them, and these are its Individual Values, or IVs. (Older documents may refer to them as DVs; they mean the same thing.)

At Lv. 100, a Pokémon with a 31 IV in its Attack will have a stat that is 31 points higher than another Pokémon of its species with a 0 IV in its Attack. You cannot influence IVs after the Pokémon is captured; whatever it rolls, it is stuck with.

Determining Individual Values

Of course, like most high-level concepts in Pokémon, IVs are hidden and must be determined. The easiest, and most practical way to do this quickly is to use an IV Calculator and a bag of Rare Candies (about 20-25 are good for determining stats exactly, though 10 should do in a pinch). You can also have an "IV Battle", where you engage in a Wi-Fi battle with someone for the sole purpose of seeing what your Pokémon's stats look like. You write them down and then you both quit.

Let's take a look at an example. I have recently hatched a Cherubi, and want to know what its IVs look like. In an IV battle, I see the following:

Health: 220
Attack: 77
Defence: 126
S. Atk: 143
S. Def: 122
Speed: 92

In order to work out the IVs, we need to know Cherubi's potential range of stats in the wild. We can do this using a stat calculator (such as the UPDB Stat Lookup). These are the ranges.

Health: 220 (200 ~ 231)
Attack: 77 (75 ~ 106)
Defence: 126 (95 ~ 126)
S. Atk: 143 (129 ~ 160)
S. Def: 122 (111 ~ 142)
Speed: 92 (75 ~ 106)

Note that they are all 31 points apart. From here, it's simple subtraction to determine what the IV is. For Health, the 231 - 220 is 11, so this stat is 11 off from 31, or 20. Attack is 106 - 77 = 29; 31 - 21 = 2. And so on. Note that this particular specimen has perfect Defence; 31.

Obtaining Good Individual Values

If you want to catch a Pokémon with high stats, you're going to be at it for a while. The chances of randomly encountering a Pokémon with six 31's is 1 in 1.07 billion. That's... insane. Rather than spend sixteen lifetimes trying to do it that way, we can breed instead. Refer to the Breeding document for the particulars.

It's important to make this distinction now- if you care about stats at all, beat the game first. If you like your starter or Pokémon you catch along the way, it is best to breed them and start again. For a number of reasons, trying to train battle-ready Pokémon while playing through the main game is far more difficult than it needs to be.

Do not stress yourself out trying to obtain six 31's. Most Pokémon have at least one stat that is almost completely irrelevant to it. A Rhyperior, for instance, has such low Speed and S. Atk that it really isn't worth worrying about them- it should never be using attacks that aren't running off its Attack stat instead. And in most cases, a few points difference isn't going to matter in the long run. The only exception to this is Speed, where one point CAN make a huge difference in battle. Health is the next most important, since a point of Health is worth a point towards both defences. The other four stats... don't freak out too much if they're not perfect. I tend to think anything 26 or higher as quite good. Other players have different limits they're willing to set.

Lastly, you cannot breed Legendary Pokémon, so you may have a hard time getting one with the stats you want. You may have to make a compromise here- though you can affect the Nature in Diamond/Pearl with a Synchronize Pokémon, you still have to catch it yourself, and leave yourself prone to fate. This is the tradeoff for (most) Legendaries being very powerful, as a Legendary with mediocre IVs may still be more powerful than a regular Pokémon with good IVs.

Natures

Of course, it'd be too simple if that were it. All Pokémon have a Nature, which increases one stat by 10% and decreases another by 10%. When determining IVs, make certain to remember that this bonus is applied last, and doesn't change the IV itself. For instance, if Cherubi above had had a 10% penalty to its Defence, the stat would be 113, but its IV would still be 31. The bonus, incidentally, would make it 138. Always round down when dealing with decimals.

IV calculators can take natures into account, so don't worry too much about them. When deciding what your Pokémon's stats should be, you should have a nature in mind already. Unlike most things related to advanced Pokémon training, you can influence your Pokémon's Nature fairly easily.