What are EV's?
Effort Values of EVs are trainable values. Every Pokémon has a maximum of 510 EV points in their life with a maximum of 255 in any individual stat. EVs are player input and will not rise by themselves, in similar matter they won't disappear by themselves. In short; for every 4 EVs in one stat, the Pokémon will get a +1 boost for that particular stat at lvl 100 on a neutral nature. This is slightly more if the nature is beneficial (~*1.1) and lower if the nature is hindering (~*0.9).
Example:
A Pokémon with 160 EVs in Special Attack will get a +40 boost in Special Attack at lvl 100.
A Pokémon with 163 EVs in Special Attack will also get a +40 boost in Special Attack at lvl 100 due to the fact that 163 isn't divisible by 4. The 3 extra EV points are wasted.
This means that, even though there's a maximum of 255 EVs in one stat, you'll get the same effect with 252. Meaning an extra 3 EVs you can spend on another stat.
Do note that EVs will only be truly visible at lvl 100 and rise according with their level. A Pokémon with 252 EVs in one stat at lvl 10 will only have an average of +6 (Normally this is +6.3, but the game rounds everything down) in that stat and an average of +31 (+31.5 rounded down) at lvl 50.
After your Pokémon received 510 EVs, he can't get any others. So you can freely kill anything after this.
How do I train EVs?
EVs are gained whenever a Pokémon is beat, there's no way to stop this from occurring, you can only remedy this (see EV-Lowering Berries). EVs are given to all Pokémon who participated in a battle. Each Pokémon gives out a certain amount of EVs. There's no way that this will vary. A Starly lvl 5 will give the same amounts of EV as a Starly lvl 100.
Example:
For beating 41 Starly, your Pokémon will gain 41 EVs in Speed. Seeing as the amount of EVs Starly gives is one and they're spent on Speed.
For beating 41 Pidgeot, your Pokémon will gain 123 EVs in Speed. Seeing as the amount of EVs Pidgeot gives are three and they're spent in Speed.
For beating 41 Unown, your Pokémon will gain 41 EVs in Attack and 41 EVs in Special Attack. Seeing as the amount of EVs Unown gives are split. 1 for Attack and at the same time 1 for Special Attack.
As you can see in the example showed above, some Pokémon give split EVs. Generally, you'd want to avoid these Pokémon as they give EVs to both stats. Possibly, a stat you wouldn't want to train.
If you want to know which Pokémon give out EVs in what stat and how many of them, I recommend utilising Serebii.net's PokéDex:
HP|Attack|Defense|Special Attack|Special Defense|Speed
So if you want 252 EVs in Speed, you'd need to beat 252 Starly (just an example). This is very painstaking and time consuming. For that reason, there are items and tricks that'll make this chore go a lot faster.
Macho Brace and PokéRus
Macho Brace:
Equiping this item doubles the EVs gained from any Pokémon. Example: Defeating a Starly gives you 2 EVs in Speed now. This effectively makes EV training twice as fast. The only downside to the item is, is that it cuts the holder's speed to half its normal amount, making your Pokémon twice as slow. PokéRus:
This once elusive disease for Pokémon (now far easier to obtain due to WiFi) also doubles the EVs you gain. Downsides? There are none. You'll reap the benefits while not having to face any sort of cutdown.
In order to pass PokéRus over to other Pokémon, the Pokémon with PokéRus must be in your team. After a few battles, your other Pokémon will get infected. Do note that after some time (this is; every Pokémon that's in your party with PKRS when the game hits midnight (00:00)), your Pokémon will create immunity against PokéRus (PKRS will become a smiley like this: ). Meaning your Pokémon will no longer be able to pass down PokéRus to others (it will still get double amount of EVs, though). Therefore, it's in your best interest to box a Pokémon with PokéRus, seeing as boxed Pokémon can't get or lose PokéRus status, for future "infecting".
Using these two at once also works, granting you a 4x the amount of EVs you'd normally get.
So if you needed to beat 252 Magikarp for max Speed, they suddenly became only 63 Magikarp.
EXP Share
EXP Share not only shares EXP, but gives the Pokémon that's holding it the same amount of EVs for the Pokémon that's beat (do note, therefore not always the same to what the Pokémon that beats it gets)!
Example
Your fully EV trained Infernape beats a Starly. While he gets 1 Speed EV, your lvl 1 Pichu that's holding EXP Share also receives 1 Speed EV.
This is the best way to raise newly hatched Pokémon.
And remember, this CAN be used in conjunction with PokéRus (obviously, this means that the Pokémon that's holding the EXP Share must have the PokéRus). Meaning twice the amount of EVs.
Due to a lot of confusion. YOU DO NOT GET THE SAME AS AMOUNT OF EVs AS THE POKÉMON THAT BEAT THE POKÉMON, BUT MERELY THE SAME AS IF YOU WERE BEATING THE POKÉMON.
Example:
Your Infernape is holding a Macho Brace and has PKRS, your Pichu is holding an EXP Share and does not have PKRS. Your Infernape beats 1 Starly. While he gets 4 EVs in Speed, the Pichu only gets 1, since it gets the same as if it beat the Pokémon itself.
Example 2:
Your Infernape is holding a Macho Brace and has PKRS, your Pichu is holding an EXP Share and also has PKRS. Your Infernape beats 1 Starly. While he gets 4 EVs in Speed, the Pichu gets 2, since it gets the same as if it beat the Pokémon itself, but it also has PokéRus, so the EVs it gained were doubled.
Hope this clears up a lot of confusion and misconceptions.
Power Items
These 6 items grant an extra 4 EVs in one stat after battle. Even if the Pokémon that was beat gives out other EVs, they'll still receive EVs in correspondence to the held items. They also lower the holder's Speed by half like Macho Brace does.
Power Weight – An extra 4 HP EVs after battle.
Power Bracer – An extra 4 Attack EVs after battle.
Power Belt – An extra 4 Defense EVs after battle.
Power Lens – An extra 4 Special Attack EVs after battle.
Power Band – An extra 4 Special Defense EVs after battle.
Power Anklet – An extra 4 Speed EVs after battle.
Example
If the holder defeats a Starly while holding Power Anklet, it'll receive 5 Speed EVs (1 Speed EV from the Starly + 4 Speed EVs from Power Anklet)
If the holder defeats a Gastly while holding Power Anklet, it'll recive 1 Sp. Attack EV and 4 Speed EVs (1 Sp. Attack EV from the Gastly + 4 Speed EVs from the Power Anklet)
The Power items can be used in conjunction with PokéRus to get an additional +8 EV gain after battle. Definitely items you need to get!
Vitamins
You know those very expensive items such as Protein that cost 9800 PokéDollars? Ever wondered what they did?
These Vitamins not only raise your Pokémon's happiness but also a certain stat by 10 EVs!
This is the order:
HP UP – Gives your Pokémon 10 HP EVs
Protein – Gives your Pokémon 10 Attack EVs
Iron – Gives your Pokémon 10 Defense EVs
Calcium – Gives your Pokémon 10 Special Attack EVs
Zinc – Gives your Pokémon 10 Special Defense EVs
Carbos – Gives your Pokémon 10 Speed EVs
Do note that these no longer work if a particular stat already has max EVs (255) or if all your EVs are already spent.
They also no longer work if you gave a Pokémon 10 of the same item already.
Also they only work if the Pokémon doesn't have over 100 EVs in the stat they raise.
Example:
If you gave your Pikachu 10 Carbos to raise its Speed, you can no longer give him any Carbos.
This means this method is only good for raising your Pokémon's EV up till 100. If you want to max it out (an additional 152 EVs), you'll need to beat Pokémon.
EV-Lowering Berries?
A fairly recent addition; EV-lowering berries.
How do they work? Quite simple. Give the Pokémon a certain berry to eat and it lowers their EVs of that stat to 100, and dropping them by 10 each use after that.
Pomeg Berry – Lowers a Pokémon's HP by 10 EVs.
Kelpsy Berry – Lowers a Pokémon's Attack by 10 EVs.
Qualot Berry – Lowers a Pokémon's Defense by 10 EVs.
Hondew Berry – Lowers a Pokémon's Special Attack by 10 EVs.
Grepa Berry – Lowers a Pokémon's Special Defense by 10 EVs.
Tamato Berry – Lowers a Pokémon's Speed by 10 EVs.
Something useful if you might've made a mistake or accidentally killed a wrong Pokémon.
EV Training Spots Diamond/Pearl/Platinum
Diamond Pearl and Platinum have plenty of great spots for EV training, with a lot of pokemon giving 2 EVs and even 3 in some cases. Let's have a look at some of the best places to find these pokemon...
HP EV Training
So you want to bulk your pokemon and give it the best chance at surviving that crucial hit? The HP EVs are what you need!
Shellos and Bidoof outside Valley Windworks give +1 HP EV each. Gastrodon outside the Fuego Ironworks give +2 HP EVs each Even MORE Gastrodon outside of PalPark also give +2 HP Evs each
Attack EV Training
You want your prized pokemon to rip apart the foe asap? Then Attack EVs are your destiny!
Kricketune. Yes we know it has an annoying cry, but these common dudes give out a nice +2 Attack EVs each time. Bibarel also give out 2+ Attack EVs, but are less common... HOWEVER, head over to the rainy route [Route 212] and you can find both of these pokemon here.
Defence EV Training
A rock hard defence is vital to any team, and by training for Defence EVs, you can guarentee you'll see your pokemon survive more hits.
Iron Island is the perfect Defence EV training paradise. It contains Geodude [+1], Graveler [+2], Onix [+1] and Steelix [+2], all of which drop vital Defence EVs.
Hippopotas and Geodude can be found in the cave, just off Route 214, each giving +1 Defence EV.
Special Attack EV Training
So you have your mighty special sweeper in mind, but need to pump up it's Special Attack? Then go Special Attack EV training!
Gastly in the Old Chateau inside Eterna Forest give +1 Special Attack EV each, and if you put your GBA Game in the GBA slot whilst here, you could be lucky enough to spot a Haunter [+2 SAtk] or even a Gengar [+3 SAtk].
You can also battle Golducks outside the Resort Area by Surfing, giving +2 Special Attack EVs each.
Special Defence EV Training
Taking Special hits is just as important as the Physical ones, so training in Special Defence wouldn't be a bad idea!
Tentacool [+1 SDef] and Tentacruel [+2 SDef] are your best bets, found by Surfing pretty much any Ocean or Sea area. Mantyke's can be found north of Sunyshore Town, and give +1 Special Defence EV.
Speed EV Training
Want to gain the upper hand in battle? Going first is about as important as how hard your attack hits, and can easily determine the outcome of a battle.
Raticates and Fearows Northwest of the Fight Area [+2 Speed EVs each] Zubats [+1 Speed EV]/Golbats [+2 Speed EVs] in most caves. Starly on Route 201 are great early game spots in case you want to EV train something early on, giving out +1 Speed EV each.
EV Training Spots Heartgold/Soulsilver
----------
| Attack |
----------
Location: Route 42 (Surfing)
Pokemon: Goldeen (1), Seaking (2)
Levels: 10-25
Comment: These are the only Pokemon you'll find in this route, which makes it
quite a good hotspot.
-----------
| Defense |
-----------
Location: Route 45
Pokemon: Graveler (2), Geodude (1), Gligar* (1), Skarmory* (2)
Levels: 23-27
Comment: Good training spot, and there's lots of grass to choose from. Gligar
is exclusive to HeartGold, while Skarmory is exclusive to SoulSilver.
Location: Victory Road (All Floors)
Pokemon: Onix (1), Rhyhorn (1), Graveler (2), Bronzor* (1)
Levels: 32-36
Comment: Bronzor can only be found through Sinnoh Sound. Okay-ish spot. Sorry
to anyone who used Donphan since it actually gives 1 Attack and 1 Defense.
------------------
| Special Attack |
------------------
Location: Route 43
Pokemon: Flaaffy (2), Girafarig (2), Mareep (1)
Levels: 15-16
Comment: A nice route, as the first wto are the most common. Unless you also
want Speed EVs (which is still good), run away from the Pidgeotto.
Location: Ilex Forest [Surfing]
Pokemon: Psyduck (1), Golduck (2)
Levels: 5-20
Comment: What's up, ducks? It's a shame Golduck's quite rare.
-------------------
| Special Defense |
-------------------
Location: Route 34 (Walking and Surfing)
Pokemon: Drowzee (1), Ditto (1), Tentacool* (1), Tentacruel* (2)
Levels: 10-12; 10-29
Comment: Earliest one, and it's not that good. I only really mentioned it
because of how abundant Drowzee is. Tentacool and Tentacruel can only be
found through Surfing.
Location: Route 41
Pokemon: Tentacool (1), Tentacruel (2), Mantine* (2)
Levels: 15-25
Comment: The only thing this route has that other surfing routes don't is
Mantine. The only problem is, it's exclusive to HeartGold. Should you want to
kill more jellyfish, Tentacool and Tentacruel can be found in almost all the
places where you can surf. I only put this one up because of Mantine.
---------
| Speed |
---------
Location: Route 38 and Route 39
Pokemon: Raticate (2), Rattata* (1), Meowth* (1), Plusle* (1), Minun* (1)
Levels: 13-16
Comment: There are a lot more Pokemon you can battle in these routes, but
the first three are the most common, so it's an okay-ish spot. Rattata will
only be found in these routes if you're playing HeartGold, and likewise for
Meowth for SoulSilver. Plusle and Minun can only be found through the Hoenn
Sound. Note that both routes have the same Pokemon.
Location: Route 7
Pokemon: Spearow (1), Rattata (1), Raticate (2), Murkrow* (1),
Meowth* (1), Vulpix* (1), Persian* (2), Plusle* (1), Minun* (1)
Levels: 15-19
Comment: This area is much, MUCH better if you're playing SoulSilver, as the
final three Pokemon [Meowth, Vulpix and Persian] are exclusive to that game.
Furthermore, Murkrow is only available at night, while Spearow is only
available during Morning and Daytime. Plusle and Minun are available through
Hoenn Sound.
Location: Route 9
Pokemon: Rattata (1), Raticate (2), Spearow* (1), Fearow* (2), Linoone* (2)
Levels: 13-15
Comment: Like Route 7, this area is better in SoulSilver, since these will be
the only Pokemon you'll see in the route's grass. HeartGold doesn't have it
bad, though, since their exclusives, Mankey and Primeape, both give Attack EVs,
which means this route is really good for Physical Attackers. Spearow and
Fearow are only available during Morning and Day, while Linoone is only
available through Hoenn Sound.
Location: Route 10
Pokemon: Raticate (2), Voltorb (1), Electabuzz (2), Spearow* (1), Fearow* (2)
Levels: 15-18
Comment: Unlike the previous two routes, the Pokemon here are available to
both versions. Yay. Spearow and Fearow are only available during Morning and
Day, while Linoone is only available through Hoenn Sound.
------
| HP |
------
Location: Union Cave [First Floor, Surfing] AND Cliff's Edge Gate [Surfing]
Pokemon: Wooper (1), Quagsire (2)
Levels: 10-25 / 20-40
Comment: Cool spots, and they'll be the only ones you'll find for both places.
For Cliff's Edge Gate, though, you will need Rock Climb to access it, but you
at least get higher-levelled Woopers and Quagsires.
Location: Slowpoke Well [First Floor, Surfing]
Pokemon: Slowpoke (1)
Levels: 5-25
Comment: Yup, it's the only one you'll find when you SURF, so enjoy killing
Slowpoke! x_x
Location: National Park [Nighttime]
Pokemon: Hoothoot (1)
Levels: 10-14
Comment: Don't like Surfing? Go to National Park at Nighttime and enjoy all
the Hoothoot. HeartGold users have Caterpie as an option during Morning and
Daytime, which also gives 1 HP EV.
Location: Route 15 Nighttime
Pokemon: Nidorina (2), Noctowl (2), Quagsire (2), Chansey (2)
Levels: 23-25
Comment: I like this spot, and I can't believe I missed it in Version 1.0.