A few days ago, I made my first attempt at trying to determine a pitcher’s value knowing their pitch grades. Since it was published, I have made some adjustments to the pitch grading scale. With the new scale in place, I have been working on comparing grades a pitcher previously received to their actual performance. The results have been extremely disappointing.
In the original article, created a framework to grade individual pitches with an ERA equivalent value (pERA) and a scouting grade on each pitch. While I liked the overall framework, one part really bothered me and I will address the issue first.
The change was to put some consistency in pitch grades, especially with fastballs. The problem was that a pitcher’s fastball is getting graded because of its velocity, but that velocity changes depending on if the pitcher was a starter or reliever. Relievers can really ramp up their velocity when moving to the bullpen.