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Alberto Arias: The dark horse of the 2009 Astros?

Last season, when the Astros acquired Alberto Arias, I initially read of the transaction and just shrugged my shoulders because it didn't seem like a big deal.  Then I pulled up his Baseball Reference minor league page, just to see what I could make of his stats.  The thought process went like this:

  1. Age: 24  Good, someone under 30.
  2. 2.24 K:BB career, in the minors...for the Rookies farm system—especially Colorado Springs—pretty good.
  3. 6.99 K/9 career, in the minors...for the Rookies farm system—especially Colorado Springs—damn, that's good.
  4. Age: 24
  5. Hasn't been a starter since 2005: Crap.
  6. Age: 24
I was mildly impressed.  Young, with good enough stuff to have survived the thin air of Colorado Springs and walk away with some his best numbers there—sign me up.  Then Arias made a start on Sept 8, 2008 that took that mild sense of hope and made me just salivate over Arias' stuff.  He went 5 IP, 6K, 3BB, 3H, 0R, 0ER.  It was an impressive performance...even if it was against the Pirates.

Of course, 10 days later, Arias would toe the rubber against the Marlins, but would only survive 2.2IP, 2K, 3BB, 5H, 2R, 2ER.  So not that impressive, but let's take a look under the hood to see whether or not Alberto Arias, at 25, could be the dark horse in the Astros rotation in 2009.

According to Fan Graphs, Arias throws a Fastball (74%), Slider (9.9%), Curveball (15.9%), and Change Up (0.2%).  He's relying on his fastball an exorbitant amount, which maybe why someone decided, circa 2005, to move Arias to the bull pen.  Of course, this is just his Major League data, and most of his appearances (both in 2007 and 2008) involved Arias coming from the pen.

Looking to his brilliant start on Sept 8, 2008, doesn't do much to dissuade me that Arias doesn't rely too strongly on his fastball to find real success as a starter.  Of the 65 pitches that Arias through, 49 were fastballs (75.38%).  Without littering the post with graph after graph of Arias' pitch/fx data from that start, I'll just through out a few observations and include this link for you to peruse at your leisure.

  1. Arias doesn't do a good job of hiding either his curve ball or his slider from his fastball, but does to a good job of hiding the slider and the curve ball in each other.
  2. He has very good release point in terms of hiding his pitches.
  3. After the first inning, Arias saw a distinct drop of in velocity from his fastball.
  4. He did avoid the meat of the plate fairly well.
He was good, but not great.  My guess is that he survived by avoiding the meat of the plate, but not by much else.

To determine if Sept 8, 2008 actually holds anything, in terms of insight, for us, I looked at Sept 18, 2008 as a foil.
  1. His fastball was much slower than it had been 10 days prior.
  2. He through more pitches in 2.2 innings than he did in the 5 innings ten days prior (69 to 55).
  3. Leaned less on the fastball 47 times (66.67%), but was probably due to the fact that he couldn't throw it above 90 very often.
  4. His slider becomes hidden in his fastball and change-up (which he through all of twice), leaving the curve ball as it's one distinct pitch with a BIG hump
  5. Instead of staying down and in on RHB, like he did 10 days prior, Arias was on in the middle to outer portion of the plate.
  6. Release point was not very tight, and the curveball becomes some what visible in it.
  7. After the 1st inning, he only through his fastball above ninety twice.
While Arias has experienced past success as a starter in the lower levels of the minors, and was brilliant for five innings last September, I just don't know that he'll be the hark horse we need this year.  I also get the feeling that our front office feels the same way, as Arias has only thrown 17.1 IP in 16 appearances in the Dominican League this winter.  However, Arias has found great success, having whiffed twenty-two while only issuing seven free passes.  Having another strong bull pen arm wouldn't be the worst thing to happen to our team given that Geary and Sampson will be question marks until they prove otherwise, due to their respective off-season surgeries, and the inherent question marks in Backe, Moehler, and Hampton.

Who knows though?  Maybe this winter Arias has polished his curveball or change-up and won't have to rely on the fastball as much.  I won't bank on it, but it's not out of the question as he will only be 25 (which in Astros terms, makes him about 21) and thus still has some space between here and his ceiling.  While Arias may best be suited as a reliever, he clearly has the ability to be a starter—if he can stay down in the zone and polish on of his breaking pitches.

As of now though, I'm not going to call him the dark horse.