Friday, September 04, 2009
Pitch f/x nomenclature
Posted by Dan NovickI've always been an avid reader of baseball analysis and sabermetrics. Pitch f/x in both research studies and on Gameday has been a specific point of interest, although I've never gotten around to doing any research (of consequence) of my own. But the main thing on Gameday that always bothered me was the column in the pitch-by-pitch section titled "BRK" which stands for "break."
I had been reading pitch f/x studies before I noticed this "BRK" column, and realized it was different than either the horizontal movement or vertical movement that had been quoted in those articles. Well I went on for months not really knowing what BRK actually meant. It was never quoted anywhere, so I figured it must not be important. I eventually asked Mike Fast to explain it to me, and it was pretty damn simple. I felt kind of embarrassed I had never taken the time to figure it out before or ask anybody what it actually meant in real terms.
For those of you who were in the same predicament as I was a long while back, I'd like to share this piece by Dave Allen over at The Baseball Analysts, which explains the difference between break and movement. For the sake of Mike Fast's inbox, I suggest you go ahead and check it out.
Dan Novick is a lifelong Yankees fan, and still gets the chills every time Enter Sandman plays from the Yankee Stadium speakers. He welcomes comments and questions via e-mail.
The difference between “movement” and “break”, as this was discussed extensively in a THT article by John Walsh two years ago:
http://www.hardballtimes.com/main/article/in-search-of-the-sinker/. Since then, there has been lots of discussion at the blogs about which of the two is more intuitive to the players (I think the consensus was “break”) and which was more useful for baseball analysis (consensus was “movement”).