Jonathan Papelbon, RP
Fast fact: Retired the first batter he faced in 49 of his 59 appearances; retired the side in order in 26 of the 53 innings he started.
Lowdown: No longer concerned about his arm, hence the desire to go year-to-year on his contract, Papelbon has become an absolute force at the end of games. He didn't allow a single run in 10 2/3 innings in the playoffs, capping a stellar season. He's now working on refi ning his slider, which he threw when he was starting.