To make room for Ryan Garko on the 40-man roster, Gaby Hernandez was designated for assignment. Which is just as well, seeing as Gaby Hernandez isn't legally permitted to work for another three years.
Anyhoo, while the exact roster implications of this move aren't yet clear, our best guess is that the bulk of Garko's duty will come as the right-handed half of a platoon at first base. He'll get some time at DH, he'll make some pinch-hit appearances, and he may even spend a few innings behind the plate showing Rob Johnson where the ball's supposed to go, but first base is the obvious fit, as Casey Kotchman is a lefty who has enough trouble hitting righties.
On the surface, it's a nice upgrade. Kotchman comes in with a career .277/.334/.388 line against southpaws. Garko, meanwhile, checks in at .313/.392/.495. That's a huge boost in OBP and a huger boost in SLG, and with a name like "Garko", you know this guy can hit the crap out of the ball when he gets into one. He's a threat to go for extra bases whenever he steps in, and on a team like this, a lot of people have perceived that as a critical need.
You have to apply some regression, though. By hand, Garko's wOBA platoon split is .341 vs. righties and .388 vs. lefties. That's a ratio of 1.14, against a league-average ratio of 1.05. I could go in depth here if I wanted to, but I don't, so you should just trust me and the good fellows at The Book Blog here when I tell you that platoon splits that wide tend to regress pretty hard. If you go through all the math - and, again, just trust me - you come out with the following "true" split approximations:
Garko vs. RHP: .347
Garko vs. LHP: .371
Kotchman vs. RHP: .339
Kotchman vs. LHP: .318
Note that these are splits based on career batting data and do not account for 2010 projections. Conveniently, however, both Garko and Kotchman are projected to perform pretty close to their career levels. Science!
Right there, you can see the appeal of a platoon. Even after regression, we're still talking about a guy who we can expect to post a wOBA about 50 points better against left-handed pitchers. 50 points of wOBA are a lot of points. It's equal to about 25-30 runs over a full season, and about ten runs over a full season against lefties.
But there are a few things to remember. First of all, no platoon works perfectly. Even with Garko around, Kotchman will still end up getting some ABs against lefties, just as Garko will still end up getting some ABs against righties. And second of all, Kotchman is an excellent defensive first baseman, while Garko is not. Garko isn't a disaster in the field, but he's probably worth around -5 runs or so, while Kotchman comes in around +5 to +10. The defensive gap, naturally, eats away at some of the platoon difference. So while Garko can mash a little bit against southpaws, the platoon advantage isn't as broad as the wOBAs would suggest, as you still have to take defense into account.
Does that make this a bad deal? No, not at all. Garko's cheap. He's going to cost this team half a million dollars, and as long as he's around, he's going to provide a decent platoon bat and a little power off the bench. Assuming this means the team goes with a six-man bullpen - and, honestly, I still think that's the most likely scenario here - he gives Wak some more offensive flexibility, which is never a bad thing. Garko makes this team better by a handful of runs. But that's all we're talking about, here. A handful of runs. It's just hard to squeeze that much out of the right-handed half of a platoon, and while Garko will help, he won't help a whole lot. While it's always nice to upgrade, particularly for a team in our current situation, this is probably one of those moves that's going to have a bigger impact on fan peception than it will on the actual team.
Note: if we still end up going with a seven-man bullpen and we have to jettison, say, Ryan Langerhans, then I don't like as much.