Redefining the 80-Grade Fastball: Spin Efficiency, Spin Axis and Movement Profile

Written by: Trevor Powers (@TPowerProspects)

Follow us on Twitter! @Prospects365

Regardless of your profession, if you don’t look back at some of your past actions and beliefs and cringe, you probably aren’t living right. You might think outward humility and introspection is embarrassing, but I believe it shows a continued desire to grow and evolve, no matter your occupation.

I may not cringe when I reread my article on redefining the 80 grade fastball (my maiden article on, but I can’t help but think there must be more. For me, that means developing a desire to elaborate more on the topic of a data driven evaluation of a pitch—in most simple terms—to improve our understanding and evaluation process as a baseball community.

As I previously discussed, spin rate and vertical movement are more important than velocity when evaluating a fastball, and I still believe that whole heartedly. But there is so much more to it than the simple notion that spin rate= vertical movement or even the common misnomer that spin rate= swings and misses. While spin rate is extremely important, spin efficiency and spin axis have a larger impact on the movement of the ball, and understanding that movement is vital to the success of a pitcher.

Being able to use this information for pitch design—and pitch tunneling—can lead to success as a pitcher. On a grander scale, big league organizations that best understand and weaponize this information are the same organizations that—you guessed it—tend to make deep playoff runs each season.

The organizational ability to improve spin efficiency, optimize spin axis, locate in every quadrant and effectively tunnel full arsenals are the reasons pitchers seem to instantly improve when they put on an Astros, Dodgers, Rays, or Indians uniform. Don’t worry, other organizations are well on their way to joining this group.

To review, velocity doesn’t always correlate with the swing and miss rate of a fastball. Jordan Hicks is an example of this. While armed with a premium-velocity fastball, the pitch does not induce and above average swing-and-miss rate. He does create ground balls at an elite rate, but that outcome isn’t nearly as favorable as a whiff.

So what is the best attribute for a fastball? I hypothesized that a high-spin, vertically moving fastball creates more swings and misses than velocity. Bauer units (spin rate divided by velocity) gives us a better idea for the attributes that create a true plus offering. I still firmly believe in the use of Bauer Units to better evaluate a pitch in the simplest form of velocity and spin rate, but I now realize it’s only a piece of the puzzle.

Vertical movement is obviously important, but what I missed in the writing of the first article is how vertical movement is created, not to mention the creation and importance of horizontal movement. It’s true that a higher spin rate tends to naturally create more vertical and horizontal movement, but it’s not the only path to the promised land. Exhibit one: Josh Hader.

Spin Rate Avg Velocity Bauer Units Vertical Movement (% vs avg) Horizontal Movement (% vs avg) Whiff %
Josh Hader (2019) 2,123 95.5 22.23 12.5 (+16%) 9.5 (+20%) 40.9%
Sean Doolittle (2018) 2210 93.8 23.56 11.4 (+26%) 3.3 (-55%) 33.4%

Hader has one of the best fastball in the big leagues, but it would be quickly discarded if our sole evaluation was the 2123 RPMs. Despite possessing a below average spin rate, the 25-year-old throws his heater nearly 80% of the time, achieving a 40.9% whiff rate in the process. That makes Hader’s fastball one of the very best pitches in all of baseball. So if I am hypothesizing that a high-spin, vertically moving fastball creates the most swing and misses, how does Josh Hader obtain swings and misses at an elite rate?

What I missed in the article is something that has become apparent to me since that day: the movement profile of a fastball correlates more strongly correlates with swings and misses than raw spin rate. So as we dive deeper, the question we must answer is simple: what traits create a certain movement profile that is going to obtain swings and misses?

The answer is spin efficiency and spin axis.

In layman’s terms, spin axis impacts the direction the ball moves. The easiest way to visualize spin axis is by using a clock. For example, a ball with perfect backspin will be on a 12:00 axis. Here are multiple visuals to show that better:

Here’s spin axis in action:

The main culprit that creates a spin axis is arm slot. To a lesser extent, spin axis can be manipulated by wrist angle and finger orientation. This is important because a high-spin fastball from a 3:00 spin axis will have more horizontal movement than vertical movement, which we have deemed as a positive attribute as well.

The main difference between Doolittle and Hader’s fastballs is spin axes that create the differences in movement. Because Doolittle throws from a higher arm slot, he is able to achieve a spin axis almost at 12:00, creating above average vertical movement. Hader throws from a lower 3/4 arm slot, which creates a spin axis closer to 10:30—naturally leading to more horizontal movement.

doolittle gif


Even without slow motion, we can see the differences in arm slot between the duo (h/t Pitcher List). Take note of the location of both of their pitches as well; command certainly factors into their success with their fastball.

The fact that Hader is able to create ‘rise’ from a lower arm slot is a critical part of the deception he features and one of the many reasons his fastball is so freakishly good.

But Hader isn’t the only pitcher in the big leagues who throws from a lower arm slot. Doolittle isn’t the only pitcher who utilizes an over-the-top arm slot. Neither pitcher is an elite spinner of the baseball, so what sets their fastballs apart from most others? Spin efficiency.

Spin efficiency is how true the ball spins out of the axis it is thrown from. It affects how much the ball moves. A ball that rolls off the fingers with perfect backspin will be close to 100% spin efficiency; a ball that a pitcher might get on the side of will have a lower spin efficiency, which often creates cut or sink. A ball with 100% spin efficiency thrown out of a 12:00 axis will have a ton of vertical movement and little horizontal movement, giving the much-vaunted appearance of rise to the hitter. Doolittle does this exceptionally well. A ball thrown out of a 10:30 axis with 100% efficiency will have a lot of ‘rise’ and run. Hader does this exceptionally well. The effects of spin efficiency can be seen below:

As is shown very clearly in the video, a with 100% spin efficiency, simply put, has more ‘life’. Thrown from the same arm slot, a pitch with 40% efficiency fades into the middle of the plate while a pitch with 100% efficiency maintains its plane and crosses the plate above the zone. There is no change in spin rate, velocity or axis. The only difference changing the movement profile is the spin efficiency.

Spin axis and spin efficiency create the movement profile of the pitch. Only after spin axes and spin efficiencies are established does raw spin rate become a factor. The higher the spin rate, the more leeway and margin for error a pitcher might have with their spin efficiency. A pitcher with a low spin rate and high spin efficiency could have a similar movement profile as a pitcher with a high spin rate and low spin efficiency. When you combine high and efficient spin, you arrive at the fastballs of pitchers like Gerrit Cole, Justin Verlander and Max Scherzer.

Spin Rate Vertical Movement (% vs avg) Horizontal Movement (% vs avg) Whiff %
Max Scherzer 2474 16.7 (-4%) 12.2 (+36%) 27.5%
Gerrit Cole 2530 10.9 (+20%) 11.4 (+46%) 37.6%
Justin Verlander 2577 10.7 (+21%) 10.1 (+46%) 31.1%

The movement profiles of these pitches are extremely impressive, and you can get an idea of the spin axes each member of the trio throws from by simply evaluating their respective movement profile. Cole throws from a high 3/4 arm slot, Verlander is more over the top and Scherzer throws from a low 3/4 slot. It shows in these pictures.

Screen Shot 2019-12-30 at 10.23.45 PM

You can see distinct difference between the axis each creates. Scherzer has minimal vertical movement, but a lot of horizontal movement. Cole has a fantastic combination of both, and Verlander is similar to Cole but with more vertical movement.

Truly understanding how a pitch moves also means understanding where in the zone to locate it. If you watched enough of the playoffs, it became apparent that pitchers for the Dodgers, Astros and Brewers force fed fastballs up in the zone. It’s no coincidence that these teams have a knack for analyzing pitchers’ movement profiles and where their pitches are most effective, and creating a plan on how to attack hitters using that information. Current free agent Tony Cingrani became a poster-boy for this movement when the Dodgers acquired him from the Reds. He immediately improved post-trade, compiling a 2.79 ERA and 1.86 FIP for the Dodgers after totaling a 5.40 ERA and 7.20 FIP earlier in the season with the Reds (h/t Baseball Savant).

tony cingriani

That story is one of many that are built around pitchers being traded or signed by teams that better understand how to optimize their individual tools and skillsets. The most famous of these stories might be Cole, the now $324 million man. The Astros tinkered with the right-hander’s arsenal, ditching his ineffective sinker, relocating his fastball and unlocking the true potential of a pitcher who was selected with the first overall pick in the 2011 MLB Draft.

cole 1

cole 2

The first is Cole’s pitch usage this past season in Houston, the second being 2017 in Pittsburgh (h/t Baseball Savant). You can see the differences between pitch usage with the increase in four-seam, slider and curve with a corresponding decrease in sinker and changeup usage. The second—and most important—change was the location of his fastball. It’s evident the Astros urged Cole to focus on elevating the pitch. Does changing the location of a pitch really become the difference between what Cole was in Pittsburgh and the dominant pitcher who earned one of the largest contracts in MLB history? It plays a major role of being able to maximize his powerful raw ‘stuff’, but there’s a more important factor in play. The Astros were able to change both Cole and Verlander’s spin axis, leading to a more optimized movement profile for their respective fastballs (h/t Baseball Savant).

Vertical Movement (%vs avg) Horizontal Movement (% vs avg)
Cole (2017 Pirates) 14.0 (-2%) 13.4 (+49%)
Cole (2018 Astros) 12.5 (+13%) 11.1 (+39%)
Verlander (2017 Tigers/Astros) 13.5 (-6%) 13.6 (+71%)
Verlander (2018 Astros) 11.0 (+21%) 11.0 (+55%)

While their previous organizations prioritized horizontal movement that produced an abundance of ground balls, the Astros wisely prioritized swings and misses. Cole and Verlander were likely able to accomplish their new goal by manipulating their finger orientation on the ball instead of altering their arm slot. Once it became muscle memory, the pair was able to increase vertical movement while slightly decreasing horizontal movement. The rest is history.

Pitch ‘tunneling’ is a big buzzword in today’s game. For the uninitiated, pitch tunneling is basically the act of making different pitches look identical for as long as possible. This leads to deception further optimization of a pitcher’s arsenal. As a current college hitter, I can say that picking up spin is one of the hardest things we’re tasked to do. A lot of what we pick-up is a change in release, hand position or what is termed as a ‘pop’ out of the hand when the ball leaves the plane of a normal fastball. Watch the video below and imagine stepping into the batter’s box versus Max Scherzer.

Rob Friedman is always posting overlays, and you’ll notice a lot of his videos are of the same, star pitchers. Combining elite movement on pitches with the ability to make them look alike creates a nightmare scenario for opposing hitters. In his book MVP Machine, Travis Sawchik discusses the development of Trevor Bauer’s slider. Adding the slider to his pitch repertoire was one of the main reasons he vaulted himself into the Cy Young consideration in 2018. By understanding the movement profiles of his already-existing arsenal, Bauer was able to create a slider that looked identical to his two-seam fastball…. until it didn’t. Below is an excerpt from a Sawchik article describing the pitch’s conception.

bauer 1

Understanding the data behind spin rate, spin axis and spin efficiency can be the difference in a talented professional pitcher blending-in with the countless amount of other, replacement level big league pitchers, and meeting or exceeding their gaudy potential.

Good organizations understand the strengths of their players and prospects. Great organizations invest in resources and philosophies to create unique, innovative ways for their players to utilize and optimize their strengths. This fact led to the unlikely era of spin rate, spin axis and spin efficiency throughout baseball. I’ll leave you with a provoking thought: the sport’s next trend is currently being contrived in the basements and laboratories of organization(s) that will dominate the sport a decade from now.

Follow P365 staff writer Trevor Powers on Twitter! @TPowerProspects

Follow us on Twitter! @Prospects365

Featured image courtesy of photographer Quinn Harris and USA Today

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