Groundballs and the Bullpen: Do we need them?

In the Rockpile today, Poseidon's Fist linked an article by Dave Cameron of Fangraphs discussing the Rockies' postseason rotation. He breaks it down to Ubaldo-Cook-DLR-Hammel, leaving Marquis off of the rotation. But it isn't just "lol marquis is teh awfuls," he raises a really good point:

Marquis would give the bullpen something it doesn't have right now - a guy to come in and get a ground ball in order to induce a DP or a play at the plate.

He raises a good point. The bullpen we have going into the postseason is very strikeout-heavy, pretty much bereft of groundballers. But is that such a bad thing?

It's interesting to note that the strikeouts and groundballs seem to be inversely correlated, but that's a different study entirely.

Contrast this bullpen with the guys in 2007, just based on GB%:

Click past the jump and we'll break these numbers down.

In 2009, our 3 most extreme groundballers are all starting pitchers. Which makes sense, more or less, it helps mitigate damage via the double play and it keeps pitch counts down by getting more balls in play early in the count.

In 2007, however, 3.5 of our 5 most extreme groundballers were in the bullpen, and only Aaron Cook was in the rotation. Morales' role in the postseason was somewhat mixed, so that's why he gets the .5 for pen and .5 for rotation.

So in a casual sense, yes, we'd like a groundballer in the bullpen. But it seems, for the rationale listed above, that the groundballers are better suited to the rotation, as they are more prone to giving up hits (at least in terms of Marquis and Cook), and typically with bullpen duty, you want to get the outs as lock-downingly as possible, as to mitigate potential inherited damage.

So let's get a quick look at how 2007 and 2009 stack up in summation.

You could probably just look at that little chart and say "well, the Rockies just are a better pitching team this year" and I wouldn't argue with you at all. But it does seem that in sacrificing GB% for K/9, we made our pen better, and by further emphasizing GB% in the rotation, it made it better there as well.

The two pitchers I'd like to single out kind of embody the balance between the two measures presented: Ubaldo Jimenez and Manny Corpas.

I don't think I need to say much about Jimenez. 7.98 K/9 and 52.3% GB and he throws 700mph and he runs on clean burning biodiesel.

Corpas, however (and I'll keep this somewhat brief, I want to touch on his season more after we're all wrapped up with 2009), strikes out a decent amount, has excellent control of the strike zone (as in he never walks anyone), and still throws his slider very effectively. He also has a career GB% of 51.4%.

His sinker/2seamer/whatever we're calling it lost something this year, and there's a distinct chance we could chalk some of that up to a damaged elbow causing him to overthrow or something (this really isn't my area of expertise). He got hit a lot harder than we'd like to see, but I really think he'll rebound in 2010. He still gets a good number of ground balls, still doesn't give up many fly balls, and actually posted a lower FIP in 2009 than '08 or '07.

Frankly, and I know he was kind of awful this year, but I do think the pen missed having Corpas just for the different toolset he brought along. I mean, clearly we didn't miss him TOOOOOOOO much, but we had to rely on guys like Flores to come strike one LHB out (and he did do that pretty well: 11K to 1BB v LHB) when we had a jam to get out of. Season-long, yeah, Corpas was trouble, but situationally, he might still be a good tool to have around. But again, next season.

As for the original issue, having Marquis in the pen WOULD present us with a groundballing option, but I'm not 100% convinced I want to bring him into tight situations, especially with how wild his last start was in general. If you want a situational groundballer, you need a guy who can come in and paint corners with either  a nasty changeup or a strong sinker, locating low and getting the big double play outs. I don't see Marquis being able to do that.

Mopup guy? Sure. 3 inning relief? Sure.

Situational groundballer? ehhhhhhh I wish we had Corpas still.