Taking a look at fastball spin rate data

The data is available on the baseballsavant.mlb.com website and anyone can find it. Trying to understand exactly what it all means is a whole different story.

I am talking about spin rates for major league pitchers. No doubt, big league teams like the Orioles have reams and reams of data not available to the public and interpret it in ways you and I could only dream of. They are experts and I am a beginner. But with some help while using what is publicly available, I want to try and learn more about spin rates. And I as I learn more, I’d like to present it to the readers here.

Going to try and not hurt myself as I jump on the spin rate train.

Maybe some of you will not care a bit about this and have no interest. I understand that and today you will not be a fan of this story, I guess. Maybe others, like me, will try to learn more and understand this concept and data, which has become so important to Major League Baseball coaches, players and front offices.

I am a beginner with this data and not afraid to either say that for one or seek help or to learn more for two. I sought out Alex Fast, an associate producer at Major League Baseball and the vice president of PitcherList.com. He helped point me in the right direction in finding data and explaining much of what I found.

Today I want to take a look at only four-seam fastballs. Later we’ll look at other pitches and see how O’s pitchers stack up.

Spin rate is presented in RPMs - revolutions per minute after the baseball is released. Two of the same pitches, thrown at the same velocity but with different spin rates, will end up in different places. A four-seam fastball, thrown with backspin, has many RPMs. The average spin rate on a four-seamer in 2020 was 2,306 RPMs. Several Orioles rate above average.

Scott-Pitch-Orange@BOS-sidebar.jpgI will list them here and also list where they rank among 418 pitchers who threw 250 or more pitches last year. That is 250 total pitches, not just four-seamers, but the data I am presenting is for four-seam fastballs only. So when you see No. 6 next to Tanner Scott’s name and No. 166 for Dean Kremer, for instance, that is where they rank among those 418 pitchers. The last number is the spin rate, the RPMs, of their four-seamers.

6 - Tanner Scott, 2,656
50 - John Means, 2,458
86 - Cole Sulser, 2,409
106 - Keegan Akin, 2,389
166 - Dean Kremer, 2,321
209 - Paul Fry, 2,281
249 - Travis Lakins Sr., 2,227
352 - Alex Cobb, 2,098
366 - Dillon Tate, 2,056
393 - Jorge López, 1,910

As it relates to spin rate, here is something unique to four-seam fastballs: Both a high and low spin rate can be positive. A pitcher with a high spin rate can work more often by elevating pitches in the strike zone. These pitches tend to drop at a lower rate near the zone. They appear to throw a rising fastball, which is not possible. But essentially their fastball does not sink at the rate of many others. It appears to explode on the hitter or have some late life, as they say. A pitcher throwing a low spin rate fastball will have a pitch that drops more than others. It’s a better sinker, if you will. Tate’s low spin rate was no doubt a factor in his producing a solid groundball rate of 51.2 percent last year.

You want to further complicate this? Probably not, but I will anyway.

There is an aspect to this we call “active spin” or “spin efficiency.” That is essentially the percent of the spin that actually impacts the ball’s movement. This is quantified as a percentage. Someone with a 90.0 rating is getting 90 percent efficiency of a possible 100 percent in their spin.

Among the pitchers that were tracked with their four-seam fastball spin efficiency last year, here is where Orioles ranked among the top 300 that were rated.

27 - Cole Sulser, 97.0
33 - Alex Cobb, 96.5
38 - Keegan Akin, 96.1
61 - Jorge López, 94.6
71 - Dean Kremer, 94.3
85 - John Means, 93.9
269 - Evan Phillips, 87.3
299 - Dillon Tate, 86.3

So a good spin rate is just one element of this. The spin efficiency is also very important, maybe the more important aspect. You can look at this and see what the Orioles like about Sulser. Not only does he have a strong changeup and great numbers versus lefty batters, but he ranks third on the club in spin rate and first in spin rate efficiency on his four-seamer. The club clearly sees something to work with.

While Scott ranks first on the club in spin rate, his spin efficiency, or active spin rate, is just 69.0. The ball is spinning well and his spin rate ranks in the 98th percentile (the top 2 percent in baseball), but it is not very efficient spin yet.

Sulser on the other hand, ranks 86th in the majors among pitchers that threw 250 or more pitches last year in four-seam spin rate and 27th in spin efficiency. A nice combo. Only Sulser, Akin and Kremer are among the top five on the Orioles in both categories. That bodes well for future success with their four-seamers. Means couples a fastball that scores well in both spin rate and spin efficiency. He was throwing the pitch with great effectiveness late in the year when he fanned 30 over 23 2/3 innings his last four starts for a K rate of 11.4 per nine.

Again, this is looking at just one season and one pitch for each hurler. But the fastball is a pretty important pitch and for most pitchers, with the rest flowing off of that.

That concludes today’s class. And you thought School of Roch was the only education offered around here.

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