EV Stat | Horde | Location |
HP | Whismur | Rusturf Cave |
Attack | Shuppet | Mt. Pyre |
Defense | Sandshrew | Route 111 (Desert) |
Sp. Attack | Spinda | Route 113 |
Sp. Defense | Swablu | Route 115 |
Speed | Zigzagoon/Wingull | Route 104 |
EVs stand for Effort Values, and they are gained from experience in battles. Every Pokemon can have a maximum of 510 EVs total, and one stat can have 252 EVs maximum. Each Pokemon gives 1-3 EVs of one stat, some giving one EV of multiple stats. The amount of EVs invested in a stat raises that stat's value of the Pokemon. The best way to generate EVs is to face hordes of Pokemon with the correct EVs while having the EV trained Pokemon hold the corresponding Power item. For example, say you are raising a Beldum and you want to max out the Attack stat. A good horde to face is a horde of Shuppet, since they each give one Attack EV. If one horde is defeated without any items, then Beldum will gain 5 Attack EVs after the battle. If Beldum holds a Macho Brace, then each of the EV values of the Shuppets double, so 10 EVs will be obtained. If a Power Bracer is held, then each of the Shuppet's EV value is added four, so each is worth five, and the total outcome is 25. Since a stat can be maxed out to 252, 10 more hordes would be needed to completely fill it. There are five other Power items, one for each of the other stats, but the Macho Brace doubles all of them. Hordes can also be consistently encountered by using Sweet Scent.
Although not recommended, another way to EV train is through Super Training. There, it takes more time to raise EVs, but it does not require hordes or items. Super Training also includes punching bags that can raise stats as well, and they are obtained randomly during the journey. Punching bags are an easy way to check if a stat is maxed out. If you maxed out the Beldum's Attack stat, then you can try using an Attack punching bag on it, and if it is maxed out, it wouldn't be alllowed to use. This will also happen when all 510 EVs are used up. The progress of EV training can be seen by the graph on the right side. A yellow bar will extend to wherever the stat is raised, and will reach the edge of the graph when the corresponding stat is maxed out.