I get asked about this a lot, and I finally have an answer based on the data reported in our recent Baseball Prospectus article. Here’s my take: 1. Know Your Efficiency It is hard to generate Seam Shifted Wake effects without some gyro. I recently posted a video that explains Continue Reading
Seam Shifted Wake Zoom
On Tuesday, November 10, 2020, I hosted a public Zoom presentation on our current understanding. It was attended by 100 people (my Zoom limit) including representatives from 14 MLB teams (that I know of). Click the photo below for a link to the full presentation.
Not All Shifted Wakes Are Equal: Post 61
Twitter: @jwillyg20 It’s time to define a Seam Shifted Wake (SSW) pitch more carefully. The main feature is that a baseball’s seams can cause earlier flow separation on one side of the ball relative to the other. This asymmetric wake is what we refer to as the “shifted” wake (see Continue Reading
The Effect of Gyro on Optimal SSW Orientation: Post 60
If you are new to the idea of Seam Shifted Wake pitches, I recommend downloading and viewing this presentation which is about 45 minutes long. I realize that is a lot of time, but this is a complex topic. That said, I think the presentation is easy to understand. As Continue Reading
Seam Shifted Wake Predictions for 2020-2021
We’ve learned a lot in the last year. One thing I am more convinced of than ever: Seam Shifted Wake (SSW) pitches are common. They have been hidden from us because of the limitations of our measurement systems and well-intentioned efforts to mitigate those limitations. Based on our research, data Continue Reading
The Apparent Tilt of Seam Shifted Wake Pitches: Post 59
Conventional pitches break because of two forces, gravity and Magnus force (the ball experiences drag also, but drag his little effect on the direction of a pitch). When a Seam Shifted Wake (SSW) occurs, the forces causing break are gravity, Magnus force and the SSW force. This article will assume Continue Reading
Diagnosing and Modeling SSW pitches: Post 58
I’ve carried on about this, but if you throw a Seam Shifted Wake pitch, there is currently no way to know that it moved differently than any other pitch. I’ve known for some time that this was an obstacle to our work. I’ve been told many times that these effects Continue Reading
How to tell if you threw a SSW pitch, sinker/changeup edition: Post 57
This is a sinker/changeup edition because it is focused on vertical movement. I may tackle horizontal movement later. Say you are an ambitious pitcher looking to get ahead and have drank our Seam Shifted Wake Koolaid (it’s good!) Did the pitch work? How can you know? Note that, on their Continue Reading
UMBA 2.0
Click here for the GitHub link This new version contains a model for the seam shifted wake. Before I get into it I want to make a couple of things clear. First, there is a quote from statistician George E.P. Box, “All models are wrong but some are useful.” I Continue Reading
Killing Laminar Flow: Post 56
When you hear people describe flow over baseballs, there is frequent reference to the seams causing Laminar flow to become Turbulent. To start, I’d better explain what those terms mean. Laminar flow is what Juniors in Physics or Engineering learn about in their fluid dynamics class. It is usually steady Continue Reading
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