Whether or not a pitcher breaks out is a combination of many factors: offense, confidence, coaching, defense, health, talent, and luck. You can only predict a few of those. One sleeper I've kept my eyes on is Aaron Heilman (is he the Mets closer now?).
Grady Sizemore will have more value than Jason Bay regardless of draft position
Aramis Ramirez in 155 G will hit over .300 40 HR 110 RBIs
Brian McCann will have more value than Jorge Posada regardless of draft position