Wednesday, February 29, 2012
How will closing impact Brett Myers’ fastball?
Posted by Harry PavlidisHow Brett Myers will do as a closer and how valuable he is to the Astros in that role is not the question for this space. Just the fastballs.
Let's take a look at some quick-and-dirty numbers (four- and two-seam fastballs all together; age determined by season year minus birth year—neither precise nor seasonal). If you go by the fastballs Myers threw as a closer in 2007, it seems starting impacted Myers more than expected, and now he's lost a wee bit more fastball than you'd expect, mostly with a big dip last year. There are no park or weather adjustments, so this is back-of-the-envelope quality.
Let's take a look at some quick-and-dirty numbers (four- and two-seam fastballs all together; age determined by season year minus birth year—neither precise nor seasonal). If you go by the fastballs Myers threw as a closer in 2007, it seems starting impacted Myers more than expected, and now he's lost a wee bit more fastball than you'd expect, mostly with a big dip last year. There are no park or weather adjustments, so this is back-of-the-envelope quality.
This chart shows a gap that's around the typical 1.5 mph gap between starter and reliver velocity that Mike Fast documented here at The Hardball Times in 2010. The age effect from the back of the envelope is a little light, considering Josh Kalk found pitchers lose one or two mph a year once they are in their early 30s. Josh's study was published here in 2008, so the data he had available was limited.
The smaller drops in speed we're looking at here are most likely due to selection bias (pitchers who lose velocity don't come back next year, etc.).
In both cases, we're in the ballpark with the back-of-the-envelope approach. Put it all together, use your gut, and see if you agree —Myers will probably be around 92 and touching 94. Reasonable guess?
This chart shows a gap that's around the typical 1.5 mph gap between starter and reliver velocity that Mike Fast documented here at The Hardball Times in 2010. The age effect from the back of the envelope is a little light, considering Josh Kalk found pitchers lose one or two mph a year once they are in their early 30s. Josh's study was published here in 2008, so the data he had available was limited.
The smaller drops in speed we're looking at here are most likely due to selection bias (pitchers who lose velocity don't come back next year, etc.).
In both cases, we're in the ballpark with the back-of-the-envelope approach. Put it all together, use your gut, and see if you agree —Myers will probably be around 92 and touching 94. Reasonable guess?
Harry Pavlidis admits he has a baseball problem. He is the founder of Pitch Info LLC, His pitch classifications power the player cards at Brooksbaseball.net. Feedback, questions and comments are appreciated - Email harrypav@gmail.com and Twitter @harrypav