With talk flying around the Mariner blog-o-sphere including raves from Jason Churchill and a generally positive vibe in most circles regarding Chien-Ming Wang (recently non-tendered by the mighty Yanks), I think it's important to put this issue forward in its own thread here.
Q: Could Wang's foot injury and subsequent arm problems be related?
A: Of course they could. He was rushed back into action after badly hurting his foot on a fielding play. You ever try throwing a baseball as hard as you can while your foot is throbbing? It screws with your delivery and you end up with a sore arm. I've done it, and it's not fun.
Q: So does that mean you think his off-year in 2009 was due to injury?
A: What say all of YOU? Personally, I don't think the data supports that conclusion. Injury swoons typically come with some sign in the DIPS categories or some dramatic change in other peripherals that can be related to extremely poor command (you lose feather touch on the ball when you are in pain) or velocity drop (you can't throw max effort when you are in pain either). But neither of those things was really happening with Wang.
By The Nunbers:
0.092: Wang's BB/PA in 2009
0.070: Wang's BB/PA (Career)
3.1 / 2.5 / 2.4 / 2.0: Wang's GB/FB, Last four seasons
93.1 / 92.7 / 91.8 / 91.8: Wang's Sinker Velocity, Last four seasons
3.1 / 4.7 / 5.1 / 6.2: Wang's K/9, Last Four Seasons
48.1 / 45.8 / 47.1 / 46.2: Wang's Swing%, Last four seasons
64.5 / 63.8 / 61.1 / 56.2: Wang's O-CT%, Last four seasons
Q: So the K rate is rising...that's a good sign, right?
A: Nope. Not with the corresponding drop in GB/FB and Sinker Velocity. Neither of which could possibly have had anything to do with injuries as they began before any such problems arose. The rising K rate coupled with a decline in O-CT% (they're not putting the low pitch in play as much) and relative non-trend in SW% mean he's trading easy groundouts for longer counts, a few more walks and more Ks. He doesn't have enough stuff to make that work. Ks aren't going to save him because he is physically incapable of getting enough of them to succeed.
Q: Who are Wang's most similar pitchers?
A: Low-K sinkerball pitchers who rely on early contact and fine command...the comps include Scott Erickson, Carlos Silva, and Derek Lowe...a wide range of possible outcomes. It should be noted, however, that, in general, the higher a sinker ball pitcher can get his K rate WITHOUT lowering his GB/FB, the better his chances for sustained success.
Q: So what's the story here?
A: I'm happy to listen to alternative explanations, but here's the one I can come up with, driven by physics.
Wang has definitely lost a foot on his sinker. It's coming in 1.5 mph slower now than it used to. The harder you can throw the sinker, the more it will tend to have late life (and the less total downward movement it will possess, but the total sink isn't the relevant thing for a sinker...it's the optical illusion it causes for the hitter). The reason sinker ball pitchers tend to flame out fast and hard, IMHO, is that once they lose a tiny bit of speed on the sinker, it becomes easier to read sinker and swing only at the ones that are up enough to elevate. Wang's declining GB/FB is a harbinger of doom despite the increased K rate, if it's my analysis you're reading.
Q: Is he worth a flier?
A: He'll cost more than flier money to sign, but no...I don't think he is worth the risk.
Q: Would he be a good fit for the Ms with their stellar defense?
A: Nope. He benefits most from good infielders...the Mariners have good outfielders and mixed infielders right now. I don't think the park will help him much either...most of its' negative impact on run scoring is in lofting flyballs, not in grounders.
Just my 0.02.