Is extending Adam LaRoche a good idea?

Lots of talk from the Pirates' front office lately has centered on making a deal to keep Adam LaRoche in black and gold for the foreseeable future. To that affect, Dejan ran this item in a PG story over the weekend:

The Pirates initially made up their minds to approach Adam LaRoche about a long-term contract even before the Winter Meetings in early December. Part of the reasoning: Huntington values ballpark factor as a measuring tool, and LaRoche's left-handed power bat represents a terribly rare commodity all through the organization.

On the surface it makes sense: lefty hitter, decent pop, good age (28 in 2008). If you're going to extend someone, it might as well be LaRoche, right? Actually, I'm not so sure. There's a couple factors involved here that people rarely talk about. Let's talk about them.

The clip from the PG story clearly implies what the Pirates have mercilessly beaten into our heads the past few years: PNC Park is a stadium that favors left-handed sluggers. Does it really? Let's look at the park (in a grab from MLB.com, as are all the following graphics):The right field line is 320 feet, which is only five feet shorter than the typical right field corner. The power alley is 375, which is about normal. There's some area cut off by the Clemente Wall being a straight line rather than curved, but it's not a whole ton. I went to Bill James for verification and I found it: the park factor at PNC for homers by lefties is exactly 100. Over the last three years, the Pirates and their opponents have combined for 155 lefty-homers at PNC and 151 on the road. There's probably some benefit (the LHB HR factor at PNC last year was 107, which was probably helped by Nate McLouth taking direct aim at the stands), but it's a lot more negligible than people imagine. In fact, the biggest benefit in having lefties hit at PNC Park is the fact that they're not righties, who get killed by the giant left field.

What does that mean for LaRoche? He hit ten homers at PNC last year, compared to 11 on the road. That means we're already off to a LaRoche-like bad start in finding some kind of benefit for him hitting at PNC. If we check his hitting charts (which you can access from his player page at the Pirates' site) we can see that of his ten homers, five went over the Clemente wall and five went more towards center. If the hitting charts are accurate, it looks to me like LaRoche gained maybe one or two extra homers in right field at PNC and lost up to FOUR in left-center in 2007:If you check his flyouts (which I didn't include to reduce clutter and the number of graphics on this page) he loses maybe one more. If you look at his charts from Turner Field last year, they lend support to the idea that PNC Park hurts LaRoche's homer total:None of this is particularly new information and lots of people were saying similar things about LaRoche's power being to all fields before he even came to the Pirates. His 2007 numbers just go to confirm that notion. That means that when we talk about extending LaRoche, we're talking about extending a first-baseman with a career OPS+ of 112 that doesn't take advantage of whatever small advantage PNC Park offers to left-handed power hitters. For a team that's just starting a long rebuilding process, where's the benefit in extending LaRoche?

Addendum: In my haste, I left out a couple of very salient points I had been meaning to make. First off, in terms of righty/lefty advantage, I was only talking about home runs. It's clear there's an advantage to being left-handed in PNC Park because the park is quite hard on righties. If given a choice between an in-prime Jason Bay and an in-prime Brian Giles, the Pirates' choice should always be Giles because of the configuration of PNC Park. Of course, things aren't always that cut and dried. I also think it's mildly inaccurate to assume there's no power advantage for lefties at all in PNC (vs. the league average that is). Guys like Daryle Ward and Nate McLouth make compelling arguments otherwise. I was simply trying to point out that the advantage isn't nearly as big as people often make it out to be and that a hitter like LaRoche takes almost no benefit from hitting at PNC Park besides the fact that he's not right-handed. Because of that, I think extending him on the basis of park factor is a mistake.

Also- I don't know why the comments link is broken, but if you check the "Recent comments" box in the sidebar, you can jump in on the conversation. Then again- they're working now, so whatever. I'm a science geek, not a programming nerd.