The PITCHf/x pitch-tracking system.
Welcome to my site devoted to research related to the physics of baseball. My particular research interests are two-fold: the physics of the baseball-bat collision and the flight of the baseball. I have done quite a bit of independent research in both areas. I am also heavily involved with several areas of practical interest to the game. One is characterizing, measuring, and regulating the performance of non-wood bats, an area for which I have served on committees advising the NCAA and USA Baseball. Another is exploiting new technologies for tracking the baseball, such as PITCHf/x, HITf/x, and TrackMan, for novel uses in baseball analytics, often in collaboration with my talented colleagues from Complete Game Consulting.

This site is undergoing a major renovation, which will take place gradually over the coming months. Clicking on "Other Links" in the box to the left takes you to links that have only partially been converted to the new format. Many thanks to Ruthann Ryan Whobrey and her talented Parkland College students for their considerable help with the renovation.

Recent Research Highlights by Alan Nathan

The Knuckleball Mystique:
Using PITCHf/x to Distinguish Perception from Reality

Published January 31, 2012 at Baseball Prospectus.

Wak
Tim Wakefield throwing his knuckleball.
The knuckleball is probably the most mysterious of baseball pitches, and a great deal of mystique surrounds it. It is usually thrown at a speed significantly lower than that of “ordinary” pitches and with very little spin. ... In this article I want to focus on the common perception that the knuckleball does not follow a smooth trajectory between pitcher and batter but instead undergoes abrupt changes of direction. Indeed, it is not too difficult to find statements in the various media about the seemingly bizarre behavior of knuckleballs, such as claims that it “flutters” or “dances” or “zigs and zags” on its short trajectory to home plate. ... But do these claims have any basis in fact? ... How smooth are knuckleball trajectories compared to those of ordinary pitches? That is the question I set out to answer, utilizing the tracking data from PITCHf/x. More...

A more technical article reporting this research will be presented at the 9th Engineering of Sport Conference, July 9-13, 2012, in Lowell MA.

Dissecting a Mystery Pitch

Published January 31, 2012 at The HardBall Times.

ball-bat
Juan Rivera swings and misses at Freddie Garcia's splitter.
On April 29, 2011 during the top of the 1st inning of a Toronto at New York game, Yankee pitcher Freddie Garcia threw a split-fingered fastball to the Jay's Juan Rivera. A video of the pitch was captured by YES-MO, the high-speed video camera from the Yankees television broadcast, with sufficient resolution to allow both the spin rate and the rotation axis of the ball to be determined with reasonable precision.

More...

There was lots of discussion about this topic at Tom Tango's Inside the Book blog. Note that the first 32 comments appeared prior to the article appearing in The Hardball Times.