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Graphing 101: PitchFx (Movement)

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Let's move on in our series, today focusing on pitch movement.

  • Assuming you know how to pull data from Gameday, go here and grab you a pitcher's data. If not, go here, find a pitcher, hit "Extended Tabled Data", copy that, and paste special (text) into Excel.
  • Now, you have two options, either break the pitches up and have them show as such, or simply go with one icon for all pitches. If you want to break them up, highlight the classification column, go to "data" -- "filter" -- "autofilter" and then "sort descending". The only added hassle is having to select each set of x and y values separately.
  • Now, find the column labeled "pfx_x", this is horizontal movement.  0 means straight, -5 means five inches in to right-handed hitters, and 5 means five inches in to left-handed hitters. Make that your x-axis.
  • For the x-axis find the "pfx_z" column. This is vertical break compared to a ball with zero spin. Hard fastballs should have pfx_z readings in the double digits, meanwhile curves are usually negative. Set this as your y-axis value.
  • Fix your axis so the x-axis has a range of -15 to 15 and a similar range for the y-axis.
  • Make it pretty.

Here's the type of stuff you can create using this method, Sabathia 2008 versus 2009:

Sabathia_medium