Selecting a Deck for <strike> Fun and </strike> Profit

Tournaments are rarely won by the player who had the cleverest deck. The reason rogue victories are so memorable is that they are uncommon and unexpected. We remember the Decree Deck, the Solution, Scrounger TurboLand, and so on because we expect victories in their breakout environments from other choices. Most of the time, tournaments are won by the luckiest players making the fewest mistakes, playing the best tuned versions of consistent archetype decks. But how do players select which decks, specifically, that they will bring?