Aaron Harang PFX analysis

Cincinnati’s been searching for a reason behind the struggles of Harang over the year after having such high expectations for him coming into this year. After his latest start, he was examined and was given a preliminary diagnosis of a tight forearm. This is concerning to me because of what I have seen in my experience. During my experience, elbow problems, especially chronic Ulnar Collateral ligament injuries lead to control problems but not necessarily velocity. This has also been discussed by a authors who’s opinion I trust, Will Carroll (sorry subscription required but well worth it) being the one that I read most. With this in mind, I wanted to look at the PFX data to see if it backed it up.

First and foremost I wanted to see what the release point was for all of his starts. At first I isolated only his home starts to be as consistent as possible and see if it was a long running problem. That gave me the lines that gave me the “central” location of his average release point.
I used the median as the reference because if we use the mean, the position would be effected by outliers. The one thing you can notice right away is how inconsistent he was with his release point. Lately the last month or two, he has been right at the line or below it. This would possibly indicate a drop in the arm slot, but we can’t be absolutely sure. The side to side motion is somewhat effected by where the player is on the rubber, so we have to take this with a slight grain of salt.

What can we conclude with the above? Something might be wrong mechanically but it’s likely not his shoulder. With his reporting of forearm and elbow pain, any changes might not be significant enough to show up in the release point. We would be more likely to see changes in pitch location with elbow and forearm pain.

With that understanding, normally I would produce a chart showing a depiction of the strike zone, but with so many pitches and dates it would be too jumbled and hard to read. So instead the next chart shows how many balls, strikes, and balls that were hit into play over each start. While they may be slightly affected by the umpires’ strike zone, the general trends are true across all starts, not just the home starts.

This is really telling because except for one slight hiccup on June 8^th, he has been throwing more pitches in each outing since May 25^th when he came in relief and threw 63 pitches according to baseball-reference.com. Then 4 days later he threw 73 pitches. So in a 1 week period he threw 239 pitches. The percentages in the above graph represent the number of pitches in that category divided by the total number of pitches. Something that I find really alarming is that in the 4 -5 starts prior to the relief appearance he had declining pitch counts but then after the relief appearance he was allowed to jump back up to the previous max or even higher. For someone who has been used pretty hard the last several years, this makes me nervous.

I then did a comparison of all the pitches that were in the zone versus out of the zone before and after the relief appearance based on the PFX system and I came up with the following. The PFX system’s accuracy claims to be within a half inch at the plate so it’s incredibly accurate. Before and including the relief appearances he had 12 appearances and after the relief appearance he was in 8 games. He threw 347(43.2%) balls outside the zone and 456 (56.8%) balls inside the zone in those 12 appearances. In the 8 post-relief appearances he threw 487(43.5%) balls outside the zone and 633 (56.5%) balls inside the zone. If 0.3% doesn’t seem by much, it’s because it isn’t. That’s a difference of 6 “extra” balls after the relief appearance. I don’t think that is necessarily too significant a difference.

His control has changed a lot this year overall though. BB/9 from 2005 to present flow like this: 2.16, 2.15, 2.01, and then rises to 2.48. This really isn’t that different based on the number of Innings so far. It only amounts to a difference of 4BB in a half a season. The problem is that the difference is really just after the relief appearance. Pre-relief his BB/9 was 2.19 while after it was 3.06.

In terms of K/9, from 2005-present: 6.98, 8.3, 8.5, and then drops to 7.9 this year. This years’ breakdown is this: The same drop off after the relief appearance shows in the K/9 of 8.3 pre-relief while post-relief those numbers and 7.34. This is quite a difference of about 1.7 per start.

How is his velocity though?

Initially it doesn’t appear so. His velocity has been up and down but you notice that his fastball velocity deeply dropped off after his relief appearance on May 25^th. It didn’t just drop off for 1 start but actually for two starts before starting to rebound again. Most likely this was due to fatigue after having to throw relief that day. The first start after the relief point the release point was above the normal but the second start coincided with a clear drop of the release point. Dropping of a release point has been known to put more pressure on the anterior shoulder, biceps, and medial elbow.

Last I want to look at the movement of his pitches across starts. My assumption is that he will have less control of the movement during the later starts. The bars are only for graphical purposes only to help me guess as to how far apart the clusters are. As you can see, the last start the clusters are a lot closer together than previous ones but that just may be because it is at a different park. It does appear that they are becoming closer overall, but it is not a great difference.

This could result in the pitches moving with less bite making it easier to hit or make contact. Finally, again with a little help (mostly to make it faster) from baseball-reference.com, I looked at the percentage of called strikeouts versus swinging strikeouts. From 2005 they are: 24%, 20%, 16%, and 33%. That means that his stuff/movement was getting better and better from 2005-2007 but now in 2008 he has to rely on location. We have seen previously that his pitch location is off this year, especially after the relief appearance.

Summary: More work still needs to be done but initially it appears that there was a dramatic effect for the worse. From the work done with previous authors, control has been shown to be more effected by elbow injuries than velocity and we see it above. I don’t have enough reliable PFX data on the effects of UCL injuries, but unfortunately (from a health perspective) I’m sure we’ll have the data soon enough. Harang has been struggling mostly after the relief appearance in terms of striking people out. It appears that his pitches were more hittable or at least able to make contact and that is a symptom of fatigue or injury if over a long term. Something was bothering him with elbow since after the relief appearance according to PFX and I hope it was only a minor strain.