Pokemon EV's And DV's Guide

Deter Values's

DVs, also called IVs (from Gen 3 onward, but I shall refer to them as DVs) are values given to each Pokemon's stat at the moment it's obtained. DVs are unchangeable throughout the Pokemon's growth.

Here's how DVs work:
A Pokemon with an Atk DV of 20 at lvl 100 will have an Atk stat of 20 more than a Pokemon with an Atk DV of 0 at lvl 100. In short: DV = final increase at lvl 100. This growth is applied to all the stats.

DVs can't be lower than 0, or higher than 31. The higher the DV, the better the stat.

The move Hidden Power is determined by DV values, and DVs are also passed on through breeding (but I will not discuss that now).

Effort Values's

EVs, introduced in Generation 3, are values that make Pokemon stronger in its stats the more it trains. For a Pokemon to gain EVs, it battles against certain other Pokemon. It doesn't matter what the level is - what matters is the species.

For example, defeating a Gyarados grants 2 Attack EVs. EVs are also not split; any Pokemon that got Exp. Points in that battle (this includes Exp. Share) all get two EVs. (Psypoke's Psydex has EV readings for all Pokemon.)The maximum amount of EVs a Pokemon can have is 510, and a max of 255 per stat. EVs affect stats in the following way:
You divide the total increase by 4, and ignore the remainder. This means a Pokemon with 100 EVs in Attack will have an Attack stat of 25 more at level 100 than the same Pokemon (with the same DVs) if the second one had 0 Attack EVs at lvl 100.

Any EV gain that goes over the 255 limit is ignored. Because of this, it's not necessary to train more than 252 EVs on a stat, since you'll always end up with +63. The EVs gained by the Pokemon have the stat growth distributed over level ups. It doesn't happen all at once.

Guide by Gizoid/Bass