(Jul 5, 2015, 05:56 PM)Aether Wrote: If you're looking to battle competitively (i.e VCG), the level cap is 50. That being said, without a fully trained pokemon you will be out classed every time. To stand even a small chnce you need to at least fully EV train, and you can tell when this has happened as your ST screen will notify you. The max EV's a pokemon can have is 510, and is capped at 252 per stat. Smogon has good EV spreads for most pokemon or you can use pokemon showdown to calculate spreads yourself.

The fastest way to EV train is with power items and horde battles. For this you will need: Power items (e.g power bracer), Exp share turned on, a pokemon with sweet scent (or honey) and a pokemon with a multi pokemon hitting move (e.g heat wave). Pkrus is optional but it does double your ev gain which is quite useful.  
Give the power item to the pokemon you want to train, find the horde that gives the correct EVs upon defeat ( ORAS horde list: http://nuggetbridge.com/articles/ev-training-horde-hotspots-pokemon-omega-ruby-alpha-sapphire/ ), sweet scent then clear with the sweeper. EV's are also passed through exp share so there's no need for the pokemon being trained to actually battle.

Each pokemon usually yields 1-2 EV's when defeated. Power items add 4 and pkrus doubles EV gain, therefore in a horde encounter you'll be receiving (1+4) x 2 x 5 = 50 EVs, making it infinitely faster that ST which yield max 12 every minute or so.

This being said, nature and IV's also play a big role in competitive battling, as a perfect pokemon will beat an imperfect one most of the time.