Is Joakim Soria the Same Pitcher as Last Year?

In a FanShot I stated the Soria was not getting the same amount of break from pitch to pitch. I decided to compare his results so far this year to Spring Training, the WBC and last using Pitch F/X data.


Here are some unrelated points to the on the game on 5/07/09, I found useful/interesting in my work and maybe some else will also:


  1. Soria is not a very consistent pitcher in the amount of break on all of his pitches. I think this is what makes him good. Hitters don't see the same stuff from him twice.

  2. Soria never threw when Pitch F/X system was set up in spring training (4 appearances) or in the WBC (2 appearances) so I can't see if changes happened pre-season..

  3. He rarely uses the slider, curve and change-up compared to the fastball, at times never using one or more of the non-fastball pitches at all.

For the above reasons, I am pretty much only able to look at the average differences in Soria's fastball until he has thrown more non- fastball pitches this season to look at those pitches. With his fastball, there is a major change from this season to previous seasons in that it is breaking ~2 more inches more in the horizontal direction. All of the other factors measured by Pitch F/X remain constant (e.g. speed, release, etc).. Here are his averages for the past 3 seasons:


Season Horizontal Break
2007 -1.0
2008 -1.3
2009 -3.5


As you can see, his fast is just breaking more, which leads us back to yesterday were Soria just seemed frustrated on the mound. His extra 2 inches of break on his fastball was putting his fastball out of the strike zone on few occasions. Here is a graph of his actual fastball and the location of the same fastball in 2 inches less of break:




Although it might just be a strike or two difference during that in inning, it sure would have help with the way his was struggling. I am going to keep an eye on his pitches and will give an update in the future, especially after he has thrown enough non-fastballs to make some kind of good conclusion considering how variable he is with those pitches.

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