Long: The case for long-form movement

From Jeff Long at Baseball Prospectus on December 14, 2017:

This paradigm for describing pitch movement focuses on short-form movement, and that’s what we’ll call it moving forward. Why is it called short-form? Well, this method of displaying movement compacts the window we view pitch movement through to compare all pitches to an origin that would be created by a pitch with 100 percent gyro spin–that is, a pitch with no spin-induced movement.

This gives us the familiar look of fastballs that move “up” on account of their backspin, and curveballs that drop on account of their topspin. Frankly, it’s a clever way to display pitch movement because it clearly highlights how spin begets magnus forces, which begets movement.

There’s just one problem with only ever viewing a pitcher’s arsenal through this lens: it doesn’t reflect reality. To better reflect the actions of pitches in the real world, we need to look at long-form movement.

Read the full article here: https://www.baseballprospectus.com/news/article/36603/pitching-backward-case-long-form-movement/

Originally published: December 14, 2017. Last Updated: December 14, 2017.