2020 Seam Shifted Wake Leaderboards: Post 68

This made me realize it was high time that I made one. First, the best SSW T-shirt is this one:

There are other boards out there. BaseballSavant.com has one I use often. Click leaderboards and then pitching and spin. For any given pitch type, you can sort on the “Deviation” which is the difference between the spin direction and the actual direction the ball moved. The results should be similar to what you see here except they are presented in clock units and LHP and RPH appear on opposite ends. In many cases, MLB categorizes pitchers differently also.

I will present these leaders in terms of deviation also. I’ll note that deviation is not always the best metric. This shows how much seam effects changed the direction of the ball but tells you nothing about how much it moved as a result. Near the end of this article, I will point you to an analysis that is more about movement.

I definite “Deviation” as the difference between the “Observed Axis” (what HawkEye directly measures with photographs of the ball) and Inferred Axis (based on how it moves and assuming only Magnus effects movement). Without further ado, here are the top 10 sinker deviations (in degrees) for more than 100 sinkers in 2020:

And changeups:

Glenn Healey and Lequan Wang recently posted an article (Click here) that isolates any force that is perpendicular to Magnus, which SSW sometimes are. In my opinion, any “side force” is from SSW, but there is likely also SSW force in the Magnus direction. Still, this is a really neat way to look at the problem and they have some interesting leaderboards in the paper.


This is my favorite stuff. Jared Hughes showed me that you can use seams to push your sinker one way and a 4S the opposite way. And I love this. I lost a bet to him about how common it is. Here is a list of the pitchers with the largest difference in the deviation between their sinker and 4S. Note that some pitchers actually spin these two pitches somewhat differently. This list is limited to seam effects. The numbers are the total difference in the deviation on the sinker and the 4S. Note that these deviations on the two pitches have opposite signs. For example, as shown above, Keller has 36º of deviation on his sinker. He also has -15º of deviation on his 4S for a total of 51º.

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2 thoughts on “2020 Seam Shifted Wake Leaderboards: Post 68

  1. Hello! Mr smith !! I always enjoy your blog.

    I just want to hear your opinion about the possibility that is able to measure SSW on Pitch Logic 3D Explorer.

    Do you know Pitch Logic? It’s a kind of pitching measurement tool. Here is the link “https://www.pitchlogic.com/metrics”

    They had released a new service as a 3D Explorer. I thought that if 3D Explorer is real pitch orbit then, It is possible to measure SSW. I asked Pitch logic customer service about 3D Explorer

    This is what they said about that.

    “pitch Logic measures the aerodynamic forces on the ball and measures movement. In addition, the seam orientation is measured and displayed in the 3D explorer.
    The 3D explorer shows the actual motion of the ball both before and after the release point”

    Don’t you think is it possible to measure SSW on the Pitch logic of 3D Explorer?

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