Wednesday, May 29, 2024

What’s in a Pitch: The Oversimplified Basics

We’ve all seen it and participated in this before. You see a nasty pitch thrown by someone on the TV while you sit in your living room, office, dorm room, etc., and you wonder how the hell they grip the baseball to make it move like that. However, this leads to a common misconception about any pitch, which is that placing your fingers on a different part of a baseball will magically allow you to throw a baseball in the likeness of Chaz Roe‘s slider or Stephen Strasburg‘s curveball, which is simply not the case. So without further ado, let’s look at oversimplified characteristics of baseball pitches.


The grip isn’t the only factor in pitch creation, but it is a major component. Have you ever tried throwing a curveball using a traditional 4-seam fastball grip (as seen below)?

Embed from Getty Images

It is extremely difficult and near impossible to do so for a few reasons. The first being that a fastball grip tends to be fairly neutral and natural with very little tension throughout the arm’s motion of the pitch. You pick up the baseball and, no matter what seams your fingers happen to cross, you will almost instinctively have a 4-seam grip on the baseball similar to the picture on the left. All that’s left to do is throw it (an oversimplification of a complex process, I know, but bear with me). A curveball grip is not natural or intuitive, and learning the curveball is almost always achieved by asking someone how to throw one and learning from their experience and then messing around with the pitch yourself.

When you throw a curveball, you have natural, unconscious, and internal timing mechanisms as to when you begin to supinate (rotation of the forearm and hand so that the palm faces forward or upward also), at what point your fingers and forearm begin to tense in preparation of the release, when and where you release the baseball, and at which point and what time you impart pressure on the baseball with your fingers and thumb upon release. All of these mechanics and timings will be different than the mechanisms of a fastball because what you are trying to make the ball do is different and unnatural.

Humor me for just a second: when our ancestors first used rocks – or any other projectile – as weapons, was their first idea to try and make the rock spin a certain way so as to break sharply downward to fool another caveman or an animal into thinking its trajectory would be straight? No, they wanted to throw that rock or projectile as hard as possible at the desired target. A curveball – and in a way, anything other than a max effort fastball – goes against thousands of years of instinct and evolution to throw the crap out of a projectile on the shortest trajectory to the desired target. Another fundamental aspect of a certain grip is that if you ask a hundred different pitchers how to grip a curveball, you’ll most likely have sixty-plus variances of the exact same grip, and the remaining thirty-some-odd pitchers will have a strange and otherworldly grip that doesn’t make sense at all (like Marcus Stroman‘s pitch grips below).

Embed from Getty Images

Every individual has a different way of arriving at the same destination. Assuming standardization is almost always a mistake, especially in a sport that is inherently high variance and individualistic, especially when it comes to the aggressive art of pitching. From the layman’s perspective, it may be as simple as “put your finger here, put your thumb here, and throw.” Instead, the mechanisms of a pitch – even a simple 4-seam fastball – can be complex and confusing if one decides to take the time to learn the physical properties that a pitch possesses, especially when you have to throw the pitch to a small target 60’6″ away.

Moreover, the reason it’s difficult to throw a curveball with a four-seam grip is that the grip is not as conducive to the pitch’s desired spin or movement, which is why different grips exist in the first place. A 4SFB grip will have your pointer and middle finger lay across the horseshoe of the baseball, while a curveball grip will typically have your finger alongside the horseshoe unless you’re weird like Sonny Gray. If it were as simple as just switching the angle of your wrist, there would be no reason for different grips to exist.


While it’s theoretically possible to throw every type of pitch from any arm slot, some pitches will be more difficult – if not impossible – to throw with certain arm slots. Furthermore, some pitches and movement profiles will be unfavorable when considering where one’s arm slot is and what other pitches are in one’s repertoire. For example, throwing a 12-6 curveball from the sidearm slot is nearly impossible.

Spin seen from
Photo Courtesy of Matt Lentzner of The Hardball Times

As one can see from the image on the left (as seen from the viewpoint behind the pitcher’s hand), a right-handed pitcher throwing from the sidearm slot has the predisposition to throw a curveball as more of a slurve, with a 9 o’clock spin direction (see Spin Axis and Spin Efficiency section below for a more detailed explanation of spin axis). Illustrated to the bottom right is a beautifully spun 12-6 CB with a 6 o’clock axis and a true 12-6 trajectory. Imagine trying to throw a baseball with that spin and movement from the sidearm slot. The wrist angle and hand orientation upon release would be very difficult to attain, much less replicate with any sort of consistency.

Gif courtesy of Driveline Baseball

A slightly overrated and highly misunderstood factor of a pitch is its raw RPM (revolutions per minute). It’s understandable when many refer to a pitcher’s raw spin as something to marvel at when guys like Justin Verlander, Walker Buehler, Sonny Gray, Gerrit Cole, and Charlie Morton top the RPM leaderboards on Baseball Savant, all with great fastballs and deadly breakers. For example, there are a few spin leaders that possess not-so-great results with their high-spin fastballs in 2019:

There are also some notable players with average 4-seam FB spin that have great results in 2019 (except Doolittle, whose stats are from ’18):

Suffice to say, raw spin is not nearly as important as the spin axis of the baseball upon release – resulting in desired spin efficiency creating the “rise effect” – and pitch location, nor does having a high spin rate guarantee a pitch to be successful.


Spin axis measures how the ball spins directionally and is explained via numbers on a clock or in degrees. When one thinks of an axis of a baseball, they tend to think of the point in which the ball is spinning around, like the north and south poles on Earth. However, spin axis is simply a measure of which direction the ball is spinning. Below are two images describing what traditional pitch axis (or spin direction) looks like visually and how pitches would be described. For example, a right-handed, 4-seam fastball could be described as, “spinning at 210 degrees,” or, “spinning at 1:00.”

A baseball has two components to its spin: transverse spin – the spin that contributes to pitch movement – and gyroscopic spin, spin that does not contribute to pitch movement. Gyro spin can be visualized as the spin of a football or a bullet, which is why it is often referred to as rifle spin. Let’s work through an example to better understand these components and how they work. Let’s say that you have two pitches: both fastballs, both spinning at 2400 RPM. One fastball has 2000 RPM of transverse spin and the other has 1500 RPM of transverse spin. Both have the same spin but, clearly, the fastball with the higher transverse spin (or “useful” spin) will be the more desired pitch because of the lessened effect of gravity on the ball due to the Magnus force, giving the pitch the famous “rising effect.” Driveline Baseball does an excellent job at simplifying what Magnus force is:

If we picture a four-seam fastball, which is thrown with backspin, the more backspin the less the ball is going to drop over its course from the pitcher’s hand to the catcher’s glove.

Here is a great gif illustrating this effect. This ball is traveling to the left with backspin, meaning the ball is pushing the air downward behind it creating an equal and opposite force upward. So you can see the faster the backspin the faster the air is deflected downwards and the higher the force pushing the ball back upward.

In other words, the more spin on a fastball, the greater the “rise” effect on the pitch. Furthermore, higher spin efficiencies can lead to greater Magnus forces and weaken gravity’s effect on a fastball even more, which is why spin efficiency is the more desirable trait on a pitch rather than just raw spin. The same things are true for a 12-6 curveball, as the Magnus force adds additional downward force to the baseball instead of counteracting the effect of gravity like a fastball would, with higher spin efficiencies aiding the pitch movement as well. On the other end of the spectrum, fastballs at lower RPMs will typically have more sink, depending on its spin efficiency. But let’s be clear, not every pitch should be spun at high efficiency. Sliders, for example, are typically thrown much harder than a curveball and naturally have lots of gyro spin, which is not necessarily a bad thing. Given the limited backspin and front spin on sliders (and the lessened Magnus force because of it), sliders will drop much quicker than a fastball due to the effect of gravity being much stronger on the ball, albeit less so than an efficient 12-6 curveball. Sliders with higher spin efficiencies will be closer to a cutter, which can still be an effective pitch, but not an ideal one if you’re actually looking to throw a slider.


“In running through this with analytics departments I have worked with over the last 14 years, velocity is the No. 1 predictor of success.” Billy Eppler spoke those words in an interview for the Los Angeles Times in 2018. And let me just say, he’s not wrong:

Hitters versus fastballs 94MPH or less

Table courtesy of Baseball Savant

Hitters versus fastballs 95+ MPH

Table courtesy of Baseball Savant

Velocity also plays a greater role when it comes to weaker contact and better results within the heart of the strike zone. Take Dylan Bundy, for example, who was one of the pitchers listed in a previous chart for possessing a high-spin fastball with poor results. Despite having high spin, resulting in 2.3 inches more positive vertical break than average, his fastball gets torched. Why? Well, as they say in real estate, location, location, location:

Dylan Bundy 4SFB location courtesy of Baseball Savant

I don’t think I need to tell you that this just isn’t ideal. But, while looking at another pitcher with a high-spin fastball that produces the same vertical break, has less horizontal break, and produces far better results (.368 SLUG, .388 xSLUG, .265 wOBA, and .279 xwOBA), we see this pitch location:

Walker Buehler 4SFB location courtesy of Baseball Savant

Also not ideal? But here’s the thing, while Bundy’s fastball averages 91.1MPH, which is 2.3MPH below league average, Buehler’s fastball averages 96.5MPH, which is 3.1MPH above league average. Higher velocity allows the hitter less time to see the baseball which allows for larger margins of error, which is why average velocity continues to rise.


Tunneling (or mirroring) is the ultimate art of deception, and effective tunneling is one of the most satisfying things to see from a pitcher. Pitch tunneling is the concept of mirroring different pitches so that the path of the pitches look the exact same until they reach the point in which the batter would commit to their swing, and then they break in different directions. Here are some examples below (All gifs courtesy of @AugustineMLB on Twitter):

If you ever wonder why a hitter swings at a pitch so far outside the zone, it’s probably because it was a) filthy, and b) the pitch was probably mirrored well. Hitters already have to deal with 100+ MPH sinkers – looking at you, Jordan Hicks – and 93MPH sliders (Jacob DeGrom). Mirroring is just the icing on the cake for pitchers, and the path to a short walk back to the bench for hitters.


No matter the pitch and no matter the fix, there is one “it factor” to make any pitch a good pitch: confidence. A fastball can have elite “rise” or sink, and an offspeed pitch can have the bottom fall out, but without any sort of confidence (whether that be not feeling comfortable with the grip or unsure if you can locate it), a pitch’s potential effectiveness is often neutralized. Your best versus their best. As a pitcher, the odds are already in your favor, and it’s up to you to show the hitter what you got. As Max Scherzer says, “Every hitter I face, I’m going to sit here and say, ‘I believe I’m better than you in this moment.’ Even though you might not be, you’re going to have the confidence that you are.” At the end of the day – or, at bat, rather – you’ll know whether or not your stuff can cut it in the long run.

And while there are far more things to learn about a baseball pitch with far more detailed analysis, let’s just stick with the basics for now.

RESOURCES TO LEARN MORE/SOURCES I LEARNED FROM,sl_avg_spin,ch_avg_spin,cu_avg_spin,si_avg_spin,fc_avg_spin,fs_avg_spin,fastball_avg_spin,breaking_avg_spin,offspeed_avg_spin,&chart=false&x=ff_avg_spin&y=ff_avg_spin&r=no&chartType=beeswarm

Aaron Plotsky

Aaron is a college student who loves baseball, writing, and learning. The game has been with him ever since he first threw a ball at the age of three, and his love for it has only evolved since. Aaron is currently an instructor and travel baseball coach at Pitch 2 Pitch South in Burnsville, MN. He is married to his beautiful wife, Jessalyn, and they share their home with their cat, Louise, and their dog, Buddy.