>>14101766picking 2 stats is generally much more useful for an offensive pokemon, since the two stats are generally speed and the offensive stat. Defensive pokemon, however, usually max HP and then one of the two defensive stats. However, if a pokemon could have another stat raised, then imo, offensive pokemon would then raise HP most of the time while defensive pokemon would raise the other defensive stat. EVs increase base stats by approximately 25%, which is quite useful since it makes many of the 1HKOs into 2HKOs and so on.