A collection of thoughts on Stephen Strasburg

Yeah, I'm late to the party on this one, but I wanted to share some of what has been written in the blogosphere about Stephen Strasburg's elbow injury.

To start this post off, here are two quotes from my March 2009 analysis of his mechanics after watching him pitch against TCU:

His flexed elbow moves well behind his back and reaches shoulder height before the ball. From there, he must forcefully externally rotate his arm to get the ball to driveline height. This causes late forearm turnover and increases the valgus torque that occurs during reverse forearm bounce. This is a risk factor for his ulnar collateral ligament.

Strasburg has some of the common flaws of traditional pitching mechanics and carries with him the associated risks. These risks will almost certainly not affect his draft status because it could be 10 years before anything goes wrong.

The second quote is included to give context for my analysis.

Around the same time as my analysis, Kyle Boddy (then writing for Driveline Mechanics - the now-defunct SBN blog) compared Strasburg's mechanics to those of Pedro Martinez and Mark Prior. The three pitchers demonstrated striking mechanical similarities.

Notably, Pedro Martinez pitched relatively injury free for most of his career until his age 34 season, the one exception being rather severe shoulder inflammation in 2001.

Mark Prior, of course, was not as lucky. After initially injuring his shoulder in a baserunning collision, Prior suffered from a string of elbow and shoulder injuries. Some people blame the collision for his problems, and while it seems like a possibilty, it is impossible to know for sure.

After Strasburg's injury, Kyle wrote two articles concerning Strasburg and elbow injuries in general.

His first article (Elbow Injuries and What Causes Them (Stephen Strasburg Bonus Content!)) is a lengthy discussion of how horizontal shoulder abduction -- referred to as "scap loading" or "scapular loading" by some -- leads to increased horizontal adduction velocities that increase valgus stress in the elbow. He notes that while this clearly can't be labeled as the sole contributor to Strasburg's injury, it certainly played a role.

Kyle's second article (Strasburg, The Inverted W, and Pitching Mechanics) attacks some misconceptions and naysaying about the reputation of the inverted W position. In his discussion, he brings it back to Mark Prior by comparing Prior's peak horizontal shoulder abduction position to Strasburg's peak horizontal shoulder abduction position.

Finally, Eric Cressey offered his thoughts -- The Skinny on Stephen Strasburg’s Injury. Much of the article explains how important the health of the anterior forearm musculature (flexor-pronator mass) is in helping take valgus stress in the UCL. He briefly tackles overall tissue quality and links back to the great series he wrote on elbow pain.

Cressey puts some of the blame on the inverted W, but he is quick to mention that mechanical quirks like that aren't always a sign of impending injury.

A lot of people subscribe to the idea that a pitcher "only has so many bullets" in his arm. Cressey quotes J.P. Ricciardi and seems to agree with him. The idea is hard to argue with, since "so many bullets" could be 1,000 or 1,000,000 or even 1,000,000,000.

As a stand-alone theory, it leaves a lot to be desired, and leads to a series of questions:

• How many bullets do I have?
• What's the best way to conserve my bullets?
• Can I get more bullets? If so, how?

With a boiled-down, unexplained idea like this, people are likely to misapply it by any number of means. That could include keeping strict pitch counts to protect the arm but still pitching year-round without rest. Alternatively, some people may wind up thinking that there's nothing they can do to extend the life of their arms and then neglect appropriate strength and conditioning.

Cressey, however, applies idea very well in a brief discussion of how to save those bullets. If you haven't read his thoughts, you should.

I have some of my own thoughts to share about Strasburg, but it may take me some time to pull them all together. Stay tuned.

Scouting Stephen Strasburg, San Diego State University... in 40 degree weather

When Stephen Strasburg took the mound in the bottom of the first inning, it was a very breezy 45° outside. By the time he was done, it was a brutally windy 39°. The wind was blowing straight out to left at Lupton Field, and when TCU second baseman Ben Carruthers hit an 0-2 pitch just beyond the outfield fence to lead off for the Horned Frogs, it looked like it might be an interesting night.

As it turned out, the Carruthers homerun was a blip. Strasburg responded by retiring the next 14 hitters in a row, 10 of them on strikes.

Game: March 27, 2009 vs. TCU

Pitcher	IP	H	R	ER	BB	K
Strasburg, Stephen	8.0	3	2	2	1	14

Fastball. 91-99 mph. Strasburg fought with the wind in his face all night but maintained command and got ahead of hitters all night long. He started in the mid-to-upper 90s, but fell to 91-94 after the fourth inning when the wind really picked up. I don't think his body was responding well to the cold, and his fastball command suffered causing him to work off his curveball in the late innings.

Curveball. 81-84 mph. Even when the TCU hitters guessed correctly, they had little chance of squaring up on this pitch. Throughout the night, Strasburg located it with ease, throwing it wherever he pleased. TCU hitters chased it out of the zone all night.

Change up. Rarely thrown. I saw a pitch at 87 mph and a couple in the mid-70s. I'm not sure which was his change up or if either pitch actually was his change up. He was essentially a two-pitch pitcher for all 8 innings.

Mechanics. Strasburg has very traditional mechanics with excellent hip and shoulder rotation, but with what looks like a rough follow through. The clip below shows 4 pitches at 210 fps and 2 pitches at 420 fps with at least one fastball and one curveball at each speed. (Kyle Boddy at DrivelineMechanics.com took a brief look at Strasburg's mechanics this past winter.)

Strasburg starts his delivery with an easy leg pick-up. He then gathers himself before stepping forward and really driving off his back leg. Right before he lands, he turns his front hip to square his landing leg to the plate. He has a soft landing on the ball of his foot, but he then drives backward with his landing leg. This creates great hip rotation but stops his center of mass from moving forward.

Strasburg does not use a pendulum swing to pick up the baseball. He takes the ball behind his back and accelerates it toward third base as he brings the ball to driveline height. His flexed elbow moves well behind his back and reaches shoulder height before the ball. From there, he must forcefully externally rotate his arm to get the ball to driveline height. This causes late forearm turnover and increases the valgus torque that occurs during reverse forearm bounce. This is a risk factor for his ulnar collateral ligament.

When Strasburg's center of mass stops moving forward, his trunk flexes forward while his shoulders rotate and his elbow again moves far behind his shoulders. He drives his pitching shoulder all the way through his release. This is excellent, but it doesn't stop his arm from finishing violently across his chest. (At full-speed you can see his arm "bounce" off his rib cage.) This is a risk factor for the supraspinatus and the infraspinatus muscles of the rotator cuff.

One major plus in Strasburg's mechanics is the apparent pronated release of his curveball. It is definitely hard to see in this video, but the second to last pitch is your best chance to see it. As he releases the pitch, Strasburg's wrist quickly moves from a supinated to a pronated position. This allows him to powerfully drive the top of the baseball instead of pulling the ball down with a supinated grip. By doing this, a curveball is thrown with more velocity and better rotation.

Overall. Stephen Strasburg is a 6' 4", 220 lb beast of a pitcher. He has two plus-plus pitches right now and ace-quality command. He's putting up numbers that would have Mark Prior and Jered Weaver blushing. Whether or not he is picked by the Washington Nationals as the first overall selection in the 2009 MLB First-Year Player Draft, he will certainly command the largest contract.

Strasburg has some of the common flaws of traditional pitching mechanics and carries with him the associated risks. These risks will almost certainly not affect his draft status because it could be 10 years before anything goes wrong. Predicting injuries is folly, but identifying risk is always important.

In a few months, Mr. Strasburg will be a very, very rich man.