The Bullpen "Problem"
So, we moved Carlos Zambrano to the bullpen because Ted Lilly was returning and our bullpen was struggling, or at least that's what Lou, Jim, the media, and the fans said. They said the bullpen was struggling.
I contend, however, that the bullpen is fine, it is just mismanaged. I have proclaimed before and I shall proclaim again that John Grabow should only pitch to left handed batters. He is in every way a LOOGY, a left-handed one out only guy. However, Lou, with a mischievous sparkle in his eye, has time and again brought Grabow in to face lip-licking, salivating at the chance to pad their stats against Grabow right handers. Almost without fail, Grabow surrenders hits and walks to right handers.
So let's look at this bullpen's "problems." Let's examine what effect Grabow's misuse has had, and let's again examine if moving our ace was the right choice:
|Bullpen less Grabow||44.6||3.96|
|Provided by Baseball-Reference.com: View Original Table|
The above chart clearly presents a bullpen less Grabow would have been a bullpen improved; however, we must remember that Lou was slapping Grabow into high leverage innings (according to Fangraphs, Grabow's average leverage is at a 2nd place career high 1.25). Moreover, Grabow has been used a lot. Here's a pie chart showing our bullpen usage (less Zambrano):
So, if we used Grabow for lefties only (or, at most, one righty), we expect him to match his career levels of FIP at ~3.50. In turn, he may see his IP halve to 3. So those extra 3 innings end up going to Justin Berg or Sean Marshall (or somebody else with a neutral or ROOGY platoon split). Using Berg or overusing Marshall may result in those three innings earning a 4.70 or possibly higher FIP -- which is still way better than the Grabow FIP.
In other words, outside of the gross misuse of Grabow's talents, our bullpen has actually performed pretty well. If it were able to reach it's Grabow-less FIP as presented in the chart above, that would be good enough to be the tied for 5th best NL bullpen of 2009. For reference sake, we had the 3rd to last bullpen in 2009.
At the risk of being redundant, I posit this bullpen "problem" is a manager problem: