It seems a crazy idea. It was just a few months ago that Red Sox fans were considering the benefits of simply dumping Papelbon--declining his arbitration, spending the $12 million elsewhere, and letting 2011 be the beginning of the Daniel Bard Era at closer. Papelbon had, after all, been entirely unimpressive in 2010, blowing eight saves, picking up seven losses, and costing the Sox a total of eight games. It's not fair to expect perfection, but it was hard not to think that, with those wins back, the Sox would have made it into the playoffs.
In many ways, the negative perception still sticks with Papelbon, likely aided in no small part by a BABIP and a LOB% that doesn't truly reflect his skill. Papelbon's BABIP of .327, while inflated, isn't a huge outlier. But the fact that it spikes to .385 with men on base and .500 with men in scoring position should show a bit of why Papelbon's ERA of 3.35 is so much higher than his career-best FIP of 1.86 (xFIP for relievers is a bit of a tricky thing, but that too is quite a bit lower at 2.33).
These DIPS are fueled by an incredible 12.22 K/9 and 1.58 BB/9--all-in-all, Papelbon's K/BB of 7.75 is surpassed only by Koji Uehara and Sergio Romo, both of whom have an ERA nearly half the size of Papelbon's.
Somehow, though, Papelbon has managed to avoid harming the Sox' record at all even with his unfortunate luck. Only twice this year has Papelbon given up a lead for the Red Sox. There was, of course, the disaster against Oakland, where the Sox saw a 4-run lead evaporate in the ninth (it's worth noting that the Sox may have saved their lead were it not for some uncharacteristically bad defense from Dustin Pedroia). The only other time that Jonathan Papelbon has taken the mound with the lead and left without one came against Minnesota, when he allowed an inherited runner to score from second.
The Red Sox came back to win both games.
So what is it that has led Papelbon to this all-but-perfect season? For that, we may have to look back to his worst year in 2010. It was in '10 that Papelbon realized he couldn't rely on his fastball as he had in years past, and opted to work his slider and splitter. It didn't work out terribly well for him that year. His splitter was inconsistent, ending up in the zone when he wanted to go out and vice-versa, while his slider would hang up in the zone far too often.
This year, the slider hasn't been terribly effective on its own, but he's kept it down in the zone with much more consistency, resulting in singles or balls instead of doubles. The split-finger, on the other hand, has become a legitimate second weapon. And simply having both of these pitches as legitimate options has forced hitters to stop sitting on the fastball, which is likely the most important thing of all for Papelbon.
Whether this new-and-improved Papelbon is a piece that now figures into the team's long-term plans is another matter entirely. He's always been the sort of player who invited the question of whether he was playing at all for pride, or purely for a paycheck. He's spent the last six years waiting for the day when he finally enters free agency, and even if his price doesn't rise dramatically, committing to any closer long-term is dangerous given the typical career path of the men who fill the role. But, should the Sox choose to part ways with Papelbon, he may well be leaving them with his best side showing, and not as the has-been that many of us predicted.