Nationals Arm Race

By now, we’ve all heard the news: Steven Strasburg is headed towards Tommy John surgery and won’t be back for 12-18 months, which probably puts him out for the entirety of the 2011 season.  Analysis and observation seem to show that the acute injury was the result of a singular injury, namely his 5th inning change up thrown to Domonic Brown which left him visibly shaking his right arm.

So, what really caused the issue?  Here’s some possibilities:

1. Over-protection by the team.  I have an awful hard time believing this.  Strasburg never went more than 100 pitches or 7 innings in any major or minor league start this season.  Does that mean he was more susceptible to a major arm injury?  I seriously doubt it.  There are those pundits who blame the Nats for NOT gaining an MRI of his shoulder during his 15-day DL stint, which is similarly ridiculous.  He had a shoulder injury not an elbow injury.  If he had blown out a groin would those same pundits be saying the team should have MRI’d his legs too?

2. A mechanical change: Some analysis that i’ve read (this post by Foxsport’s Jon Paul Morosi) has quotes from unnamed scouts that say his mechanics had changed slightly, which (Morosi intimated) may have resulted in stress on the elbow that had not been there before.  To test this, compare his Pitch F/X report from his MLB debut on June 8th to that fateful day in Philadelphia  last week. Comparing the release points in these two plots shows something interesting; his release point is indeed several inches higher on average in his last game versus his first.  Comparing The 6/8 video versus the 8/21 video isn’t really helpful; the former just shows every strikeout while the latter replays the fateful pitch where the injury occurred.  One would have to see the isolated feeds side by side to really see a difference.  However, a slight mechanical change could certainly be factor.

3. The “Inverted W” Effect: There some pundits out there on the net who believe that the “Inverted W” effect (where a pitcher’s pre-release arm positions resembles an upside-down W) indicates a proclivity of arm injuries.  The name most often associated with this (the poster boy, so to speak), is Mark Prior, who had supposedly clean mechanics, threw hard and was basically out of baseball by the time he was 25.  Writer Chris O’Leary has several examples plus an entire section on Strasburg, who does exhibit the behavior.

The problem I have with the inverted W theory is that you can cherry pick from the thousands of major league pitchers out there to prove or disprove this theory.  O’Leary himself uses John Smoltz as an example of someone who had the Inverted W, saying that Smoltz “… retired due to shoulder problems.”  Uh, Smoltz made over 700 HUNDRED starts, plus had 4 years as a closer, and made 32 starts the year he turned 40.  Thats about as BAD of an example as you can find to prove your theory.

Yes Strasburg exhibits the inverted W behavior, but not nearly as definitively as poster boys such as Prior or Reyes.  But he’s never had shoulder problems, and damage to the elbow seems to be indicative of something besides the W effect.

4. Scapular Loading: some googling about his injury turned up this interesing article at Drivelinebaseball.com.  In essence, Strasburg puts undue stress on his elbow based on “scapular loading” during his windup.  The article concludes that this behavior possibly contributed but isn’t necessarily the cause.  It is worth a read though.  I don’t know nearly enough about the subject to agree or disagree to heavily.

5. Strasburg was throwing FAR more change-ups than he’s used to.  In college, he was so dominant that he could be a 2-pitch pitcher (4-seamer and curve) and pitch his way to the player of the year award.  However, in the pros 3 pitches are required and 4 good pitches are desired.  Luckily, Strasburg possessed a 91-mph circle change that moved 10-12 inches on the horizontal plane, an absolutely ridiculous pitch.  Well, his catchers noticed this too, knowing that a screw-ball like 91 mph pitch had a better chance of getting hit by lightening than being hit hard, and started calling for it more and more.  For the season he threw that pitch 16.7% of the time (according to Fangraphs.com) but by the time the fateful Philadelphia game rolled around he was throwing it more like 20-21% of the time.

The circle change is a rather difficult pitch to master.  You essentially make a “circle” with your thumb and forefinger around the ball, then throw the ball with a fastball arm-action but letting it “tumble” off your remaining three fingers.  This causes the screw-ball like reverse movement on the ball when thrown with enough velocity.  It is a great pitch; not only does it come out of the hand slower (hence the changeup) but it moves unlike any of your other pitches.  The bad part of the pitch; it causes a ton of stress on the arm.  Your wrist and fingers are very strong and contribute to the natural fastball motion; by taking them out of play with the circle-change you use a lot more of your forearm and elbow to “throw” the pitch.

Conclusions: in the end, it is difficult to  know exactly what happened.  I personally believe the over-reliance on the circle change was his downfall, but the other points (mechanical changes, inverted-W tendencies and scapular loading) are difficult to discount.

In any case, Tommy John surgery is so common now amongst power pitchers that you start to hear rumblings about pitchers getting it done as a preventative measure (!!).  Jonah Keri had a great q&a session with the originator of the procedure and it makes for a great read.  So we’ll cross our fingers, hope that around this time next august Strasburg is pitching rehab sessions in the minors and is ready to go full strength in 2012.