Glenn Healey on seam-shifted wake is next. Great historic breakdown of where we’ve gotten to with optical tracking (Hawkeye).
I really liked a graphic he leaned on to show magnus movement (movement via spin) versus seam effects (air flow around back effecting movement) — first picture.
First arrow shows movement via spin. Second arrow shows movement due to seam effects (which results in total movement). I’ve never thought of movement as components like this, mainly because the info is not publicly available.
Color in the background is an intrinsic pitch value model. For first picture, darker is lower run value (better for pitcher). In the video darker color means LESS contribution of seams to movement.
Random point that stuck out: <1,000th of 1” variance in seam height has effect on movement.
@ReinselRyan jumped in after Healey and showed some awesome visuals related to Healey’s model in a practical application sense. Essentially they’re able to show how much effect an individual seam has on ball flight at different points as the ball rotates through space.
I’ll throw a video below to show this. Watch how the color on the seam changes.
Still digesting this one, super dense, but have talked to multiple people in baseball that see the application of models like this as the frontier most sharp teams are on right now, and some are probably even further along. (I hope all this is correct.)