I'm going answer this question now, knowing full well what kind of responses I'm going to get from people who probably aren't going to read the whole post.  

There may not be anything wrong with Chien-Ming Wang. 

Now, before you flame on about how he flopped against the Red Sox, I'll admit this: baseball is a results-driven game -  a win is a win, and a loss is a loss.  The manner in which a team earns a win or suffers a loss is largely irrelevant when it comes to the standings... but it's entirely relevant when looking forward and trying predict how a team or a player will perform throughout the remaining portion of the season.  So while I hate to see Wang continue to post poor results, and I really hate to see the Yankees winless versus the Red Sox this year, I am far more interested in trying to figure out what kind of contribution Wang can make over the remaining 100 games this season.

A pitcher's wins, losses, and ERA are ultimately determined by a number of factors, some of which he can control  and some which he can't.  He can control the location of his pitches, which greatly influences the number of batters he strikes out and walks, and to an extent, he has influence over where batted balls are hit - in the air, or on the ground - based on his repertoire of pitches.  Unfortunately, a pitcher has virtually no control over the defensive prowess (or lack thereof) of the fielders playing behind him, and even the greatest pitchers can't always prevent seeing-eye singles, home runs bouncing off the foul poul, and other various whims of bad luck.

Early in the season, I'm not sure if Wang' problem was mechanical, mental, or injury-related, but his three starts at the beginning of the season were arguably the worst consecutive outings posted by any established pitcher in the 15 years that I've been following baseball.  Scratching beneath the surface, it's perfectly obvious why he struggled - when it came to the factors he could control, he stunk.  He barely managed to throw half of his pitches for strikes (55%), he walked a batter per inning, he wasn't striking anybody out (3 K/9 innings), and, uncharacteristically, he allowed nearly two flyballs for every groundball. Any pitcher would almost need to defy the laws of physics to succeed under those circumstances

So, Wang went on the DL, made a few rehab starts, and returned to the majors in late May.  And what's been lost amidst his recent run of two poor starts is the fact that his peripheral stats, the factors he can influence, have improved expononentially.  Since returning from the DL, and excluding last night's debacle, here are Wang's stats:

via i262.photobucket.com

This looks a lot more like the old Wang, the pitcher who efficiently threw a high number of strikes, was stingy with the walks, and induced lots of groundballs.  As a plus, he's now striking out batters at a much higher rate than his career average.

Read the third paragraph again.  If Wang is locating his pitches (before last night, he was), inducing more groundballs than flyballs (he seems to be), and playing in front of a solid defense (he is), could there be something else to blame for his poor results since coming off of the DL?  Anybody who is worth their weight in sabermetrics will tell you that a pitcher who allows more groundballs than flyballs and posts a high strikeout rate is one that you're probably going to want on your team.  In fact, I would challenge anybody who's going to disagree with me to find one pitcher's who's been consistently succesful while posting peripheral stats that deviate wildly from that formula.

Wang was wild last night, but the signs are there to suggest that he's closer to being the pitcher he was in previous years than the pitcher he was in April. Furthermore, whatever caused Wang to struggle last night probably wasn't bothering him a week ago, and certainly isn't the same thing that was bothering him in April.  So let's collectively wipe his April stats from our minds, and let's view last night's start as nothing more than a bad outing, realizing that Wang would have likely stayed in the game if it wasn't for his poor April and demotion to the minors.  He shouldn't be released, traded, or demoted to the bullpen or the minors based on last night's game.

A loss is still a loss, but Wang is probably still a pitcher who throws more strikes than balls, allows more groundballs than flyballs, and strikes out a batters at a good clip, and that kind of pitcher is going to help our team win more often than not over the remaining 100 games of the season.