When it comes to getting maximum value out of your fantasy draft, it's all about the sleepers.
Yes, you have to pick the right players in the early rounds to build a successful core. Landing a player who isn't worth starting by midseason is an easy way to derail your championship hopes. However, a lot more goes into building a playoff-bound roster.
Quality depth is important. Players get hurt, bye weeks exists, and some players inevitably do disappoint. Ideally, you want to have several starting-caliber buys on your bench, so that if a swap does have to be made—or, if the right matchup presents itself—you can move a guy up and continue rolling toward fantasy glory.