> PITCHf/x is a video-based tracking system that is permanently installed in every MLB stadium and has been used since the start of the 2007 season to track every pitch in every MLB game. The system consists of two 60 Hz cameras mounted high above the playing field, with fields of view that cover most of the region between the pitching rubber and home plate
> Depending on the specifics of each installation, the pitch is typically tracked in the approximate range y=5-50 ft, resulting in about 20 images per camera for each pitch
So the raw data is from two 60 Hz cameras build some time before 2007, each taking 20 pictures of a small, fast moving object tens/hundreds of feet away? The error bars on that raw data must be significant, especially when a "knuckleball wobble amplitude" of just a few inches would already be very effective.
If I'd design that PITCHf/x system today, I'd add a handful of 80 GHz radar modules, and cameras on two more axis.
Yeah, based on the description of the system I’m skeptical that the “raw” data is all that good. The author makes some assertions about it, but he’s also working with a vanishingly small sample size. He makes no attempt to compare specific knuckleball pitches with apparent wild behavior to the captured data. He just pulls data from four games of two knuckleball pitchers.
Which is weird because the gif above does seem to follow the pattern the author himself mentioned about a very-slow-spin pitch being influenced by wind against the ball’s seams in different ways as it rotates.
The famous Knuckleball pitcher Tim Wakefield of the Sox recently passed from cancer last year, his wife Stacy also passed from cancer only 5 months after.
Tim was part of the 2004 Red Sox that broke the 86 year long curse. The entire series is on Youtube and possibly one of the greatest baseball series of all time. Here's game one, enjoy:
Something I liked - "If you laugh, you think, and you cry that's a full day."
A guy threw a knuckle in tribute to Wakefield as an opening pitch this season, sorry I can't find it tonight but if someone could find it that'd be nice. Good on 'em.
Takeaway is roughly: those observing the pitch expect it to be moving in one direction, and it often is moving in a different direction, giving the illusion of a sudden change of direction. So the knuckleball is unpredictable, just not in the way that it appears to be.
The cloud of "where it ends up" is not important for establishing the difficulty of hitting a pitch. What matters is the correlation between the initial trajectory and its final location. This is the information that the batter has.
It is a bit more complex than that; what matters is the correlation between the initial trajectory and when the batter's vision believes the ball will go. The dry spitball (knuckleball) and the spitball work on the same concept (i.e., the lack of spin will cause the ball to react differently than pitches with spin).
A change up is simply a slower pitcher than a fastball, thrown with the same motion. The slower speed mean that ball, while looking like a fastball, will act differently.
The change-up is pretty well understood, I think. Use the same apparent arm motion but grip the ball differently to create a release that’s slower and may have a slightly different spin.
https://images.app.goo.gl/CtJmayDTwVrz9xwi6