How Would Kerry Wood Fit into the Phillies Bullpen?

Yesterday, Jerry Crasnick of ESPN.com reported that Kerry Wood is “on the Phillies’ radar as a possible late-inning relief option” via twitter. The hard throwing 34-year-old, who is going into his sixth season as a reliever, is said to be seeking a one-year deal. Of course, this is only a rumor and, in true rumor fashion, it will likely die out. But by looking at the numbers and Ruben Amaro’s track record, such a deal wouldn’t be so far-fetched. And hey, it might actually be good.

Wood began his career as a hard-throwing starter with the Cubs, but elbow injuries forced him to make the switch to full-time relief. Since then, he has been somewhat successful in a variety of late-inning roles for different teams. His high-strikeout, high-walk persona is no different than it was when he entered the league, as he posted a 10.1 K/9 and a 3.7 BB/9 last season. Additionally, it doesn’t appear as if his arm is running out of gas. Since 2008, his average fastball velocity hasn’t dipped below 94.3 mph.

So why would Ruben Amaro be interested in Wood? If there’s one thing we’ve noticed over the last few years, it’s that Amaro doesn’t mind paying for relievers—especially well-established ones. This is most recently evidenced by the huge deal given to Jonathon Papelbon. Coupled with being elite, perhaps Papelbon’s greatest strength is his consistency. Sabermetricians have historically been puzzled by deals like Papelbon’s—after all,  relievers don’t spend much time on the mound relative to starters, so from a WAR perspective, it appears as if GMs chronically overpay for their services. But instead of assuming that all front offices could operate so irrationally, a new idea has been surfacing in the sabermetrics community: GMs pay for predictability. Relievers are inherently limited to small sample sizes of playing time, and a result their performances are typically quite volatile on a year-to year basis. Relievers who aren’t as fungible, then, are worth more.

That brings us to Wood. Despite his reputation as being terribly injury-prone, he has actually been a relatively consistent reliever over the past few years. Since 2008, he has averaged 56 appearances per season and hasn’t pitched less than 46 innings in a given year. In terms of results, he has been rather consistent since making the switch to the bullpen. As the graph below demonstrates, his ERA and ERA estimators regularly hang around the mid 3’s to mid 4’s range.

Such a level of predictability would be welcomed in the Phillies bullpen. Papelbon seems to be the only reliever that isn’t surrounded by major question marks. Jose Contreras is 40 and is coming off a season in which he only pitched 14 innings due to injury. Antonio Bastardo began to show signs of being human at the end of last year. Michael Stutes, albeit young, has yet to prove that he is anything more than a middle relief option. And no one knows if Dontrelle Willis has anything left in the tank.

With a largely unproven bullpen, it would not be surprising to see the Phillies aggressively pursue Kerry Wood.