CSS Button No Image Css3Menu.com

Baseball Prospectus home
Click here to log in Click here for forgotten password Click here to subscribe
Strength of Schedule Report
<< Previous Article
Premium Article Overthinking It: What ... (08/29)
<< Previous Column
BP Unfiltered: Casey K... (08/30)
Next Column >>
BP Unfiltered: 'The An... (08/31)
Next Article >>
Premium Article The Prospectus Hit Lis... (08/30)

August 30, 2012

BP Unfiltered

Is Stephen Strasburg Wearing Down?

by Dan Brooks

ESPN Stats and Information published an article about Stephen Strasburg’s less-than-successful start on Tuesday that noted, “Strasburg’s velocity declined as his start went on. His heater averaged 96.6 MPH in the first two innings and 94.8 MPH after. “

Here’s that decline as graphed from BrooksBaseball.net; you can see a substantial velocity loss over the course of the start.

The natural question is how common this is for Strasburg. But how do you summarize velocity loss?

Earlier this year, I introduced a method in which the number of fastballs thrown in the game and the speed of those fastballs was related using a simple linear model to note within-start velocity loss (or gain).

I’ve replicated that analysis for Strasburg, below, for 25 of his 26 starts in 2012, using pitch tags from the PITCH INFO database.

It is true that his most recent start has the most negative coefficient, indicating the highest amount of velocity loss. But it doesn’t seem as though the coefficients overall are on a downward trend: in other words, he’s not progressively losing more velocity during each start as his innings count climbs.

Instead, I would say there’s a more or less stable pattern for Strasburg, with the exception of the one very high coefficient. As a sanity check for the method, let’s examine that game: 2012-06-13.

The plot shows a fairly obvious rise. But the point here is that this kind of rise isn’t characteristic of Strasburg; it’s much more normal for him to show something between little-to-no decline and a slight decline in fastball speed during each start. Tuesday's velocity loss was slightly out of the norm, but it's probably not a reason to panic.

*Update* A complete list of velocity coefficients for pitchers with at least 20 starts this season is available here. Not surprisingly, Justin Verlander is at the top.

Dan Brooks is an author of Baseball Prospectus. 
Click here to see Dan's other articles. You can contact Dan by clicking here

1 comment has been left for this article.

<< Previous Article
Premium Article Overthinking It: What ... (08/29)
<< Previous Column
BP Unfiltered: Casey K... (08/30)
Next Column >>
BP Unfiltered: 'The An... (08/31)
Next Article >>
Premium Article The Prospectus Hit Lis... (08/30)

Fantasy Article Fantasy Freestyle: A Few of My Favorite Dyna...
BP En Espanol: Confesiones de un falso manag...
What You Need to Know: Best of the Best
Short Relief: Our Large Retired Sons
BP Toronto
Premium Article Rubbing Mud: Half-Truths and Collision Cours...
Baseball Prospectus News: Subscription Price...

Premium Article Prospect Profile: Dylan Bundy
Premium Article Transaction Analysis: Does the Wolf Solve Pr...
Fantasy Article Resident Fantasy Genius: Avoiding the Late-S...
Fantasy Article Value Picks: Starting Pitching for 8/30/12
Premium Article Collateral Damage Daily: Thursday, August 30
Premium Article The Prospectus Hit List: Thursday, August 30
What You Need to Know: Thursday, August 30

2012-10-05 - Advance Scout
2012-09-27 - Baseball Prospectus News: Announcing the PIT...
2012-09-14 - Baseball Prospectus News: Introducing Pitch ...
2012-08-30 - BP Unfiltered: Is Stephen Strasburg Wearing ...
2012-08-17 - BP Unfiltered: Clay Buchholz Does the Splits
2012-08-14 - PITCHf/x Profile: Dissecting the Decline of ...
2012-08-10 - BP Unfiltered: A PITCHf/x Companion Piece on...

2012-09-02 - BP Unfiltered: The Justin Ruggiano Club
2012-08-31 - BP Unfiltered: Ichiro Suzuki, Mountains, and...
2012-08-31 - BP Unfiltered: 'The Anthony Molina Incident'
2012-08-30 - BP Unfiltered: Is Stephen Strasburg Wearing ...
2012-08-30 - BP Unfiltered: Casey Kelly's Debut
2012-08-30 - BP Unfiltered: This is a Mike Trout Factoid
2012-08-28 - BP Unfiltered: Steve Pearce Now Has a Story