I may have written this before, but I think I have to continue as long as I hear people saying things like "the Rangers have no other options at DH" or "Michael Young is the more potent offensively than the other options."
Simply put, here's a weighted On Base Average comparison between the three most likely options for the Rangers Designated Hitter roll. Not much commentary, just the numbers.
SCROLL PAST THIS PARAGRAPH OR CLICK THE JUMP IF YOU DON'T CARE HOW THE SAUSAGE IS MADE. For this, I adjusted each player's wOBA for home ballpark using Stat Corner's park adjustments (meaning these numbers would be higher in RBiA!). Those are hand-specific, so it's more fair than your typical park factor. For the projection, I used ZiPS. Mitch Moreland also factors in to this, but he's a small sample size issue. To arrive to wOBA, I used the individual components of ZiPS plugged in to a wOBA calculator. Base running is not included. For "Career Platoon Gain," it's the percentage improvement the player gains by facing the opposite handed pitcher compared to his career average.
Career wOBA: .359
Career Platoon Gain: 111% (.399)
Projected wOBA: .353
Projected wOBA vs LHP: .392
Career wOBA: .344
Career Platoon Gain: 103% (.356)
Projected wOBA: .339
Projected wOBA vs RHP: .349
Career wOBA: .336
Career Platoon Gain: 105% (.352)
Projected wOBA: .330
Projected wOBA vs LHP: .347
David Murphy/Mike Napoli Platoon
Projected wOBA: ~.380
Certainly a guy who can be expected to hit at .330 (again, better in Arlington), .347 at platoon strength, is nifty insurance. But if you assume Michael Young is the best guy to be DHing from the get go, anything can happily, but you're more than likely incorrect. If you assume Michael Young is the only guy to be DHing, you are absolutely incorrect. Murphy/Napoli would be a much better hitter.
This is to be a reference for you. Save it. if someone tries to tell you something along those lines, hand them this reference.