The last time I talked about fixing wangs, I was taking my poor dog to......nevermind. 

Chien Ming-Wang's return from the DL has been full of mixed results, but after three consecutive starts of 5 innings and allowing 3 runs or less, it appears that the rotation spot is his to keep, despite a rather poor ERA since May (5.28) and since returning to the rotoation (6.35).

We'll always have passionate debates about the role of analyzing stats versus evaluating on-field performance.  And while the Yankees fan in me hates to see Wang keep performing at a mediocre level, the stathead in me says something else is at play.  So to break it down, I compared Wang's stats from his heydey in 2006-2007 to his stats since returning from the DL this May, to see what was going on.  I ignored hits and runs, because those are often too dependent on factors outside of the pitcher's control, i.e. bad defense, bad luck on BABIP, etc.  I also understand that 30 2/3 innings in 2009 are a very small sample, but if we're going to run him out of town based on that small sample, then I'll take the stats for what they are.

Let's start with the basics, that is, you can't win games if you don't throw strikes, and Wang doesn't appear to be throwing any fewer (or more) strikes than he has in the past.  I know he has appeared wild in some starts recently, or hasn't had command of his sinker in others, but he's still throwing 62% of his pitches for strikes, just like he was in 2006-2007. 

What does appear to have changed, however, is his ability to get batters to swing and miss, as well as his strikeout rate.    Two extra swings and misses per 100 pitches doesn't seem like much, but it will have a positive effect on a pitcher's stat lines (eventually, at least).  His strikeout rate has also doubled; whether or not this is attributable to the extra swings and misses, better command of pitch repertoire, or dumb luck remains to be seen.  But, for now, it's still good. 

What's also interesting to note his is decreased line drive % (measured as % of his pitches that turn into line drives).  Contrary to what we might think, opposing hitters have actually hit him less hard since he's come off of the DL this season then they did in his two 19 win campaigns.  Not every line drive turns into a hit, but most of them do; two fewer line drives every 100 pitches probably translates into on or two fewer extra base hits.

Now, there are some negatives here as well.  His home run rate went from unbelievably low to slightly above average; his walk rate has increased, albeit to a still acceptable level; and, his double play rate has decreased.  Some of these can be explained; pitchers with higher strikeout rates tend to have higher walk rates, and Wang could be inducing fewer double plays because opponents are swinging and missing more often. 

Baseball is not a statistically linear game; just because a pitcher has a career ERA of 4.00 does not mean he will give up exactly 40 runs for every 90 innings he pitches.  Weird things can happen over small samples of innings, sometimes even large samples, and even though wins and losses are the only things that ultimately count, we can look at some of the hidden details and figure out if Wang is truly finished as an effective major league pitcher, or if he's simply catching some bad breaks. 

So answer me this: how is it possible that an effective pitcher is able to increase the rate at which opposing hitters swing and miss and strike out, and reduce the rate at which they hit line drives, yet sees his ERA rise by nearly 2 full runs while doing so?

There is only one answer: Bad Luck.

Wang's BABIP was .293 in 2006 and .296 in 2007.  On the other hand, his BABIP was .364 in May '09 and .347 in June '09. 

The game is played on the field and Wang must keep improving.  But, if I was ever going to wager on one player bouncing back and returning to (or improving upon) his old form, Wang would be that player.