Spin mirroring and Red Sox pitchers (another reason to love Tanner Houck)

[Hairps]

I’m a big Tanner Houck fan.

In his limited time up with the Sox this year, his sinker displayed some crazy vertical movement and his slider’s horizontal movement was among the top 20 in all of MLB.

He’s also a big seam-shifted wake guy.

And he might just be our last, best hope of keeping the Sox ‘17 draft from being a complete disaster.

But there’s another thing I noticed about him that came up during my obsessive scrutiny of all Rays-related pitcher acquisitions. (Hey, they’re a very smart front office. Sue me.):

Houck is also darn good at “spin mirroring” his pitches.

Let’s start at the beginning.

Take a look at the following video of two different pitches, rotating on the exact opposite axis from one another (apologies in advance, credit for the following clip was hard for me to track back -- Michael Augustine? Eno Sarris of The Athletic? Barton Smith of BaseballAero?):


It is very difficult for the naked eye to tell the difference between the two of them in slow motion. Now, imagine trying to do that with them coming at you at 95 miles per hour.

That’s the big-picture idea of “mirroring” pitches. If you can throw different ones from the same release point, at near the same velocity, and as close to 180 degrees difference between their spin axes, they are very difficult for a batter to track.

Here’s a Shane Bieber visual from last year that shows almost perfectly what I’m trying to say:

Spoiler: Bieber 2020

See how his 4-seamer and curveball are at almost the exact opposite sides of the “clock” from each other? Instead of a clock, think of it as a 360-degree protractor. The red and blue bars are almost exactly 180 degrees (opposite) from each other.

Anywho -- the Rays claimed former Pirates reliever Sean Poppen off of waivers a week or so ago. As I said, the Rays are very smart. What was up with that? Well, I have one idea. Look at this:

Spoiler: Poppen 2021

Again, just to provide some color around what we're seeing there -- Poppen's sinker and slider are spinning damn close to 180 degrees (opposite) from each other. Almost perfectly "mirroring" each other.

And now for the big reveal. Here’s Houck’s chart for his time in MLB so far in 2021:

Spoiler: Houck 2021

If anyone is interested in digging into the topic a bit more, here's a link dump with plenty of additional background:

https://www.drivelinebaseball.com/2019/09/mastering-the-axis-of-rotation-a-thorough-review-of-spin-axis-in-three-dimensions/
https://blogs.fangraphs.com/taking-a-look-at-spin-mirroring/
https://blogs.fangraphs.com/taking-a-look-at-spin-mirroring-part-2-misconceptions-and-practical-applications/
https://theathletic.com/2323195/2021/01/15/spin-mirroring-identifying-fantasy-baseball-sleepers/
https://blogs.fangraphs.com/taking-a-look-at-spin-mirroring/
https://theathletic.com/898914/2019/04/02/given-his-repertoire-john-gant-can-be-major-asset-in-cardinals-bullpen-cards-know-it/
https://theathletic.com/1133082/2019/08/13/sarris-what-makes-a-slider-good/
https://lancebroz.com/reporting/2019/6/20/trevor-bauer-changeup-cincinnati-reds
https://www.mlb.com/news/new-statcast-tool-measures-pitch-spin-direction

 

[Hairps]

Other Sox pitch-mirroring kings:

Spoiler: Barnes

Spoiler: Pivetta

Spoiler: Valdez

Valdez is interesting, because that graphic shows how his slider has the potential to become a real spin-mirroring weapon if he can find his release point on it and get enough confidence in it to throw it more often.

 

[StupendousMan]

Is there any correlation between the quality of "spin mirroring" and ERA, or other measure of a pitcher's effectiveness?

 

[The Gray Eagle]

Unfortunately, Houck is out with a sore flexor muscle for a few more weeks:
https://www.masslive.com/redsox/2021/05/boston-red-sox-pitching-depth-being-tested-after-injuries-to-tanner-houck-eduard-bazardo-others-we-have-to-move-on-to-our-next-options-dave-bush-says.html

Houck, Boston’s top depth starter who has already had success in the majors, and Seabold, an intriguing righty who is projected to reach the majors this year, have both restarted their throwing programs and could return to game action within a few weeks.

Houck is due back in Worcester’s rotation before Seabold, Bush said.

Hopefully he will come back strong from this injury, and soon.

“Obviously, Tanner being the most immediate depth and having him not available right now is a blow,” he said. “If we need somebody, he’s not going to be the guy right now, although I don’t think it’s that serious. He’s already back on a throwing program and we’re hopeful that he’ll be back relatively soon. The benefit with him is that he’s already built up. He has been making full starts for a while now before he got hurt. The buildup coming back will be shorter than a spring training buildup.

Houck has lots of company on the IL:

Currently, five of Boston’s top six pitching prospects (as ranked by MLB.com) are inactive, as Bryan Mata (Tommy John surgery) is out for the year, Tanner Houck (sore flexor muscle), Connor Seabold (elbow inflammation) and Thaddeus Ward (right forearm strain) are all on the injured list with arm injuries and Noah Song is on the military list as he completes flight training. That leaves Jay Groome as the only top pitching prospect who is currently healthy, but the former first-round pick is only at High-A Greenville and won’t factor into the big-league plans this season.
To make matters worse, top relief prospect Eduard Bazardo -- who has tossed three scoreless innings in two big-league games this year -- has a lat strain and will be shut down from throwing for three weeks.