The Element of Surprise

How much do you value the element of surprise in competitive play? I'm not just talking unusual sets, simply the surprise factor, as simple as an expert belt bluff, to an entire game facade (not the move) of hiding which poke your going to sweep with.

In a metagame that's largely standardized in the terms of set, ev's spreads etc, do you think that surely surprise is the optimum to success? However, is it worth carrying a few unknown entities among your team in order to keep the opponent guessing, at the cost of something proven to be more effective & reliable?

Uhh yes. Yes indead i do. Although its difficult to be entirely sneaky anymore de to team preview, you can still bluff sets and items.

My favorite is putting my Hydreigon(life orb) agains something faster than it in a choice scarf bluff . As they switch out expecting a super effective attack, BAM!! The poke they send out is KO'd by draco metor(provided its not a steal type. If so, fire blast is the way to go).

e-belt latios is quite the threat in bw2 OU. switch it in like a revenge killer on something (possibly) faster than you, the enemy switches thinking it's scarfed, and you annihilate the switch with an e-belt boosted SE move.

I know that it is not a huge surprise as a few people use it, but I use a Volcarona on a rain team and it kind of throws a few people off as it is kind of unusual to have a fire-type on a rain team, but I spam Hurricanes and the confusion frustrates everyone and after 2 quiver dances snuck in it is really hard to take down even with water pokemon in the rain.