The Red Sox acquired Scott Schoeneweis as a possible second LOOGY (lefty out of the bullpen guy). Schoeneweis has enjoyed some success at Fenway Park, but whether the sample size suffices to predict future success merits discussion.
First, the Red Sox brain trust believes that strikeout to walk ratio (K/BB) predicts future ERA better than even prior ERA. This makes some sense as it usually reflects the intersection of power and command. Trends in K/BB often have great meaning. For example in 2008 Jon Lester had a 3.21 ERA with 152 K, 66 BB in 210 innings. Last season Lester had a 3.41 ERA with 225 K, 64 BB in 203 innings. So what? Look inside the numbers...before the All-Star game he had a 3.87 ERA and after 2.82. In other words, the K/BB ratio predicted future improvement. The fact that Lester allowed only 7 homers after the break and 13 before also may have played a role.
Let's look at Schoeneweis*. In the past three seasons (139 innings), Schoeneweis has 89 K, 64 BB (a ratio less than 1.5) and allowed 21 homers including 6 last year in 24 innings. And for that production, including three saves and three wins, he has earned 10.8 million dollars. What a country! The Sox hired him to be a potential "situational lefty". Somehow, I'm not thinking he's Billy Wagner, or Sparky Lyle, or even Jesse Orosco. Let's hope that he can overcome family tragedy and regain success.
* from Baseball-reference.com.