What does pfx mean gameday

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Subscribe now. View article on legacy site. Eric Seidman. You need to be logged in to comment. Login or Subscribe. The pitch identification algorithm labels 8 different pitches, which he absolutely did not throw.

Reply to llewdor. Haha, Johan Santana loves the changeup. Reply to PWHjort. Muzzle velocity versus terminal velocity? I have a very hard time understanding why you can have 2 pitches initially thrown 90 mph and one of them slows to 85 by the time it crosses home plate and the other slows to Other than gravity, which acts in a perpendicular direction, the main force acting on the ball during its flight is the friction from the air.

That would seem to be the same for both pitches. I can understand why a pitch that starts out at 80 mph might not slow down as much as one that starts at 90 but not two pitches that start at the same speed. Any chance that what we are seeing here is measurement error?

Reply to MountainCat. I would assume wind conditions do not remain constant throughout the game, even throughout an at bat. Reply to boards. Spin would also have an effect- not every pitch will be thrown with the same rpm, even if initial velocity is the same. Reply to yteimlad. Reply to mnsportsguy1. The data can be found through mlb. If you don't have database experience you can find individual game data there. Reply to EJSeidman. Reply to PujolsEsElHombre.

How is the vertical movement factored at each stage across the path of the pitch. It seems pretty clear from the graph that the pitches fall in each time interval as they approach the plate. Thanks for the great read, just trying to understand a little better. Reply to kmbart. The fields of interest for the trajectories are x0, y0, z0, vx0, vy0, vz0, and ax0, ay0, az0.

In the dataset the standard is 50 ft though some analysts prefer to backtrack everything to 55 ft. The ax0, ay0, az0 measures acceleration of the pitch in feet per second squared in three dimensions, and the vx0, vy0, vz0 measures velocity in feet per second.

The other trajectories are calculated similarly, except you substitute y and z for x in each instance. So when you see my above flight pattern for Santana, the horizontal was excluded because you cannot see that from the first base view Note that the formula with the y's instead of x's and z's is used regardless, but for first base views we use it in conjunction with the z's.

Looking from an angle to see horizontal trajectory we would use the x's and y's, not the y's and z's. Is there a reason why the "graph" of the playing field x,y,and z planes is taken from a bird's eye view while all of the pitch data graphs are seen from behind the plate? The way the graphs are set up, it seems more intuitive to have horizontal movement be the x-plane, vertical movement the y-plane, and then your z be the distance from the ball to home plate. Reply to MHaywood Are you sure about this?

That is, there is the tendency for the direction to do as you said, but I thought PFX already took that into account and calculated the difference between the actual X axis movement and the projected no-spin X axis movement. Contents Exit focus mode. Personal Information Exchange. Is this page helpful? Yes No. Any additional feedback? Skip Submit. Submit and view feedback for This product This page. It's the max height of a pitch over an imaginary line from release point to home plate.

The MLB Gameday blog has the exact definition. Barry Zito's curve would have a high break length, while an ordinary fastball wouldn't. Wakefield ruins the idea of where a "non-spinning" pitch would end up, as his pitches don't spin, but end up in random places.

What do you mean about actually modeling the path of the pitch? That sounds pretty cool to take a crack at. You should be able to create an accurately animated model of the path of each pitch using the new gameday data. You could animate it from the point it leaves the hand to the point it reaches the plate, perhaps from different views. I think it would be an intuitive way to present the pitch data, and doesn't seem like it would be too hard to do.

You could do side by side animations of pitches from various pitchers, to get a real-time idea of how they compare. Or you could compare the same pitch from two different pitchers, or two different pitches from the same pitcher, and probably plenty of other reasons. What I think would be neat is an animated model of a 3D baseball, and show the batters view, the pitchers view, as well other views.

I think it would be really cool to do the same sort thing with the hittracker data. Is the pitch classification correct? I would have thought the curve would have had a lot more movement than is suggested by the blue dots on the graphs.

Couldn't those blue dots be change ups? I've gotten a couple of questions about the classifications of pitches and after reading them, looking some other pitchers, I think I made a mistake with classifying some of the pitches.

For Lowe and Cook, they both throw sinkers, change-ups and a breaking ball, a slider for Lowe and a curve for Cook.

I made a mistake in thinking they both had two breaking balls. The black dots for both pitchers are in fact change-ups, and not a second breaking ball. The change-ups move similar to the fastball, which makes sense from a deception point of view. The blue dots are the breaking ball for each pitcher. These charts aren't totally intuitive to read, because they are relative to a pitch that without spin. The blue dots don't mean that the pitch had no movement, but rather, they ended up where a pitch without spin would have.

The break length essentially measures the highest height of the pitch, and Lowe's slider I say curveball in the article has the highest break length for any of his pitches, so he does have movement on the pitch.

Lowe's slider might end up roughly where a non-spinning pitch would, but it has movement on the way there. Wang made his only start of the season so far in TB, which doesn't have the system and the one start I have for Matsuzaka looks like Webb's, with dots all over the place.

For whatever reason, the system has been installed in only a handful of stadiums so far, and even where it's installed, there are sometimes inconsistencies, although based on the number of pitches that some announcers credit Dice-K with, it might not be a problem in his start. Thanks for that. I hear you on the break length. I'd have thought that a curve would have had a lot of spin on it, thereby meaning it would drop a lot more than a pitch with no spin?

Is this wrong Bert Be Home By Eleven? Only the Lonely. Timmermann Catcher's Interference R. Hall of Fame Major League Baseball. Courtesy of Baseball America First-Round: 1. Rays Hawpe. Command Post April 26, Comments It would be interesting to see Silva's patterns in , when he gave up just 9 walks in IP. Very, very, very cool can't emphasize the very's enough. Chris For your first point, the fields that are listed in the XML are a bit confusing. Notify me of new comments via email.

Notify me of new posts via email. Create a free website or blog at WordPress. You must be logged in to post a comment. August 2, Glossary of the Gameday pitch fields Posted by Mike Fast under gameday , pitchfx glossary [12] Comments. The numbers increment by one for each pitch but are not consecutive between at bats. Resources for this glossary included the following: Comments, including those by MLB. The MLB Gameday blog.

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