Nick Blackburn V Nick Blackburn

We know Blackburn will never blow anyone away.  But what's the difference between one of his good starts, and one of his bad ones?

With a chance to extend the AL Central lead to a relatively wide 1.5 games last night, Nick Blackburn was once again in a position to help the Twins get comfortable in the driver's seat of the division.  But, once again, he stumbled.  So below I'll be using chart data from Brooks Baseball's pitchfx, who feed their data directly from MLB.com's Gameday readings, to see if there's a discernable reason for his faltering performance last night.

On August 18, Blackburn went eight strong innings against the Athletics, allowing just three runs on six hits.  Last night he didn't manage to get through five innings against the Angels, and while his defense didn't do him any favors, it's quite clear that between the two starts he wasn't the same pitcher.  He logged 4.2 innings, allowing six runs (three earned) on 10 hits, and he didn't strike out a single Angel batter.

For a pitcher to be effective, and for his pitches to "work", he needs to apply force to the ball.  In conjunction with velocity and drag force, how a pitcher grips and releases the baseball can cause it to do beautiful things.  Inducing spin and angle, the trajectory of any pitch is dependent on exactly how the pitcher handles the delivery.  As you can see from the charts below, Blackburn wasn't controlling his pitches as well on Saturday night as he had six days ago against Oakland in the Dome.

Spin Angle & Magnitude

August 23:
 
via brooksbaseball.net

August 18:
 
via brooksbaseball.net

The changes here are pretty drastic, since Blackburn uses spin on his balls to induce movement; more spin equals more movement.  His fastballs on August 18 were regularly spinning at 2200-2600 RPM.  Last night only one fastball broke 2200, and usually spun 1800-2000 RPM.  Both the slider and the changeup show the same symptom, spinning much slower against the Angels.  Only the curveball was consistently picking up more RPM, sitting right around 1000.  Unfortunately, while this made for a better curveball it also meant it was coming in at the roughly the same height as all of his other pitches, because relative to his appearance against the A's his fastball, changeup and slider were all pretty flat.  Angel hitters rarely had to work to pick up where the ball was coming from, because they were all coming in on the same angle.  For some pitchers, that works.  For Blackburn, it certainly doesn't...at least, not last night.

Average Pitch Virtualization, Top View

August 23:
 
via brooksbaseball.net

August 18:
 
via brooksbaseball.net

Average Pitch Virtualization, Side View

August 23:
 
via brooksbaseball.net

August 18:
 
via brooksbaseball.net

The side virtualization is a little deceiving, because once you remove the orange line (the two cut fastballs), there isn't much difference in break.  The curve stilll starts out higher before dropping off, and the fastball, slider and change have similar side-view trajectories.  The real difference is in the top view, where you can really see how Blackburn used spin to create drag force on the ball to induce movement.  Everything, especially the fastball and slider, moved better against Oakland on August 18.

Finally, looking at the top virtualization it would be easy to assume that Blackburn was actually a bit more wild horizontally.  And the fact is, he was.  On the 18th, when he threw 99 pitches (66 for strikes), 62 of the pitches hit a standardized strike zone, for a strike percentage of 62.6.  On Saturday night, he threw 79 pitches (54 for strikes), and 55 of those pitches were strikes on a standardized strike zone, for 69.6%.  But because every pitch looked different, and almost every pitch was breaking harder, Blackburn was able to be effective by pitching outside of the strike zone against the A's.  Against the Angels he was hitting the strike zone more consistently, and with a good offense like LA has that's a dangerous game to play--especially when a guy like Blackburn didn't have his best stuff.

I'm certainly not excited by the prospect of the Angels lighting up one of our starting pitchers.  But after doing this bit of research I'm a bit more optimistic because it confirms for me that Blackburn isn't a good pitcher this season just because of luck.  He's a good pitcher because when he's on, he gets movement on all of his pitches.  Some nights you have it, others you don't, and when Nick gets another chance to extend Minnesota's AL Central lead, hopefully he'll be able to step up to the challenge.