When Brandon Inge joins the Tigers -- and he will join the Tigers -- he will start at second base against left-handed pitchers, Tigers manager Jim Leyland told the media. If Leyland sticks to this, it's not the worst thing in the world. Inge can actually be a productive batter against left-handers, as he has shown during his career. If Leyland, unwilling to give up a comfortable glove even though it has holes, allows him to face right-handed pitching, then there are issues.
Leyland isn't wrong in thinking Inge could be productive when used right. But the question is, are there players on the roster who could be better?
Career splits vs. LHP / 2011 splits vs. LHP
Brandon Inge -- .265 AVG / .342 OBP / .458 SLG (.245 /.339 /.378 in 2011)
Ramon Santiago --.248 / .302 / .340 (.320/.352 /.480 in 2011)
Ryan Raburn -- .270 / .340 / .507 .(274/.321 /.486 in 2011)
I'd include Danny Worth, but there's no longer any good sites to get minor-league splits that I know of.
What it may come down to is how much emphasis you put on recent splits and how much emphasis you put on career splits. There will always be problems that arise when you use the most recent splits, mostly due to sample size issues. On the other hand, there are problems in using career splits, as early successes could mask recent declines.
We have an interesting case of that here. In 2011, Inge was horrible. He's been pretty bad since having knee surgery following 2009. Meanwhile Santiago was pretty good. If the two players continue with their recent splits, inge stealing at-bats from Santiago or Raburn makes the team worse offensively. It's doubtful to me that Inge is a big upgrade over Santiago defensively, either. So by most recent measures, you choose Santiago. And if you don't care about defense at all, go ahead and use Raburn.
Going back to 2010 splits, we see Santiago with a .313 average and .763 OPS. Inge, however, had a .254 average and .817 OPS against left-handed pitchers in 2010. Santiago had a .390 OBP. Inge had a .486 slugging. So I would surmise that 2011 was probably out of character for Inge and expect him to bounce back a bit.
Finally, inspecting 2012 spring splits, both Santiago and Inge had OPS a few points from each other against left-handed pitching. Santiago hit for average and got on base more, resulting in a .771 OPS. Inge hit for power and a lower OPS of .736.
Leyland prefers slugging -- he likes guys that bring 'em home, so he says. I think we can see where this decision came from.
TL;DR version: Leyland's decision to carry Inge to begin the year has some validity to it. If he hits against left-handed pitching like his has in the past, he'll be useful at second base. If he doesn't, he can be jettisoned. Ultimately it's not going to result in the standings looking much different either way. It really just depends whether you're the president of Team Brandon or Team Ramon.