4th Gen Question about EVs

[Seth88]

Do i need to gain each lvl up by fighting only the pkmn that gives the EVs i need? ex: i catch a pkmn and immediatly start fighting 255 ghastlys in a row for 255 sp.atk EVs, then fight 255 ratata's for 255 speed points, then just continue with the story line fighting whatever random pkmn i see all the way up to lvl 100. will i still get the pkmn's max potential sp.atk and speed or will it ditch the initial 510 EVs i gained and use the ones from the pkmn i fought while training to 100?

 

[Pokemaster483]

The 255 ghastlys and 255 ratattas will max out your EVs, and any further training will not affect these EVs. You can also equip the "power items" to your Pokemon to make them gain EVs faster though. I recommend reading a guide on EV training before you start anything

EDIT: Here is a pretty clear guide for you.

 

[bobandbill]

Answered so going to close. If you have any other question, please ask them in the Help thread sticky at the top of the section.