I've seen Pirates fans complain about Nate McLouth, and I've seen Braves fans complain about Nate McLouth, and I've seen some Orioles fans be confused when the team signed Nate McLouth this year. Many a joke was made by people (including me) about the O's - the contending O's, fighting for a playoff spot - counting on a guy who hadn't done anything in the Majors since 2009.
But it was McLouth and the O's that had the last laugh, as he hit .268/.342/.435 for the team and then .308/.321/.462 in the post-season. There is no doubt that he gave the team a shot in the arm down the stretch.
And yet, it seems very clear to me that - contra* Jeremy's post - counting on Nate McLouth to be the starting left-fielder for the O's in 2013 is not the best move.
* I assume Jeremy doesn't know Nate personally and doesn't have any actual knowledge about his state of mind and the effects thereof, so I'm not even going to address the arguments about how McLouth can be counted on to continuing playing so well in Baltimore because he's happy here. That stuff is malarkey the vast majority of the time, I think.
Projecting a player's production by looking at what he did in the last two months of a season and seasons three years prior, while ignoring everything in between, is generally wrong. Sure McLouth hit pretty well for the Orioles, but his overall 2012 batting line was just .241/.314/.380 and he accumulated 0.8 fWAR (decent in half a season of work, but not all that great).
Just because McLouth was hurt in the intervening years doesn't mean that's wiped away completely - it negatively impacts not only how much we should expect McLouth to play, but it certainly means we shouldn't ignore the generic effects of aging.
Also, McLouth had about as many plate appearances in 2012 as he did in 2011 and 2010 (each). Over the entire span, he hit .221/.320/.340 - which is quite bad for a corner outfielder. He accumulated -0.4 fWAR. Just for comparison's sake, Nolan Reimold has hit .247/.317/.447 with 1.4 fWAR (in like 400 fewer PA). But sure, McLouth is the "proven guy"*.
* Reimold needs to stay healthy, but so does McLouth, right? Counting the minors, McLouth only has like 200 more PA than Reimold over the last three years (1276 to 1067). Why is one a huge injury risk while the other isn't at all?
To expect a player to continue hitting as well as he did in less than 250 PA at the end of a season - a substantially higher level than he has in years - is a mistake that overzealous fans sometimes make, but that GMs should not.
Even beyond that, one shouldn't expect McLouth's Orioles production to continue. His .306 BABIP would have been his best ever, and his career mark is just .277. So even just adjusting that down (and you better believe his career BABIP is what's more likely to show up in 2013 than 55 games if BABIP from this year), Nate's line falls to around .242/.318/.402 - that's a below average batting mark.
There are good parts of his game - he walks at a solid clip (9% for the O's, 10% career), doesn't strike out a ton (18% for the O's, 17% career), and has a bit of pop (.167 ISO for the O's, .173 career). But those are all merely solid, not great, as evidenced by his career 101 wRC+. A batter who's been almost exactly average in his career - with most of his playing time coming in his prime age 25-27 years - is very unlikely to be better than that (or even that good) when playing his age 31 season.
So we've got a slightly below average hitter at best, probably. Defensively, the numbers and the eye-test (to me, at least), indicate an average-ish left-fielder. His career UZR out there is -3 runs per 150 games, which is actually what you'd expect given his -13 runs per 150 games career in center-field (the positional adjustment between center and left is around 10 runs). The Gold Glove he has, like many of those that are handed out, was... not necessarily deserved.
Sure McLouth is a good baserunner - about +5 runs per full season in his career, 99 steals with an 86% success rate - but that isn't enough to turn a below average offensive, below average to average defensive corner outfielder on the wrong side of 30 who can't be counted on to play all year into a player who a team that wants to contend should give a starting spot to. And beyond the overall ability, McLouth probably shouldn't be starting anyway given his platoon splits (.342 career wOBA against righties, but only .292 against lefties).
Signing him to a one-year $2-3 M contract could be OK value (all of the above does add up to a 0.5 to 1 win player), but it doesn't actually make the O's a better team (they accumulated about a win from left-field in total in 2012). It's more promising him a job and then having to rely on him to do what no one should fairly expect from him that's the issue.
I will have many fond memories of Nate McLouth's contributions to the 2012 Orioles, and I wish him all the best in trying to land a starting gig on another (third-tier) team. If he finds those opportunities lacking, then bringing him back as a 4th outfielder isn't the worst (though his inability to play center in anything other than an emergency situation hurts). (This post was more negative on McLouth than I had originally intended, but it serves more as a counter-point to yesterday's decidedly pro-Nate post.)