Scouting is a complex process. Sure, subjectivity and personal preference are biases that will always color the approach scouts take during the evaluation process. But beyond that, the task of describing in words how players differ, and what context is relevant during each player’s individual evaluation, is an entirely different type of challenge than just separating the “good” from the “bad.”

When writing scouting reports, I’m often reminded of a thought experiment that was introduced to me in an undergraduate linguistics class, wherein the professor had us each imagine a bowl of oranges on a kitchen counter. He then asked us how we would approach the task of going into another room and describing one specific orange in that bowl, such that the person we were talking to, having not previously seen the bowl of oranges, could go into the kitchen and successfully select the orange we were describing. The limits of language were clearly illustrated by this exercise. Assuming there weren’t any obviously different oranges (no tangelos or satsumas to make our delineation clear), it required us to avoid terms like “more orange” or “less squishy” because those terms lose meaning without an agreed upon reference point.

Now, baseball prospects obviously aren’t oranges, but trying to evaluate them can also leave us grasping for common language. In sifting through our prospect rankings, certain terms begin to stand out as scouting mainstays, phrases that have emerged over time in order to help describe the nuanced qualities and characteristics that make up a player’s overall profile. But without matching images to those terms, it can be hard to understand what they mean. So with that in mind, here is my attempt at bridging the gap and bringing more specific meaning to scouting terminology by way of video illustration.

This will be an ongoing series; ultimately, the aim is to build a robust video glossary that can serve as a useful supplement to the innumerable scouting reports we churn out each year. Today, we’re focusing on pitching. More specifically, we’re talking about the body movements of pitchers, and how we tend to describe them in words. These terms probably won’t be foreign to you. They might not even need much explanation; FanGraphs readers are a self-selecting group that tends to have a good grasp on these things. But by using video to illustrate these well-known terms, I’m hoping to aid in your digestion of our scouting reports moving forward; to retrieve the right orange, as it were.

So without further ado, let’s get into it.

Arm Slot
Sometimes referred to as a pitcher’s arm angle, arm slots are easy to understand. It all comes down to where a pitcher’s throwing hand is when he releases a pitch. The subcategories are easy to understand as well, with “overhand” (or “over the top”) being the highest and “submarine” being the lowest. Tread Athletics has a more rigid definition for these terms, including the exact measurable angle of a pitcher’s arm as compared with a straight vertical line (which makes sense, as their focus is more on sports science and coaching mechanics rather than scouting). But we’re leaving the protractor out of this and will simply refer to how the angle looks to the naked eye.

Here are some video examples of the various arm slots you’ll see us refer to in our scouting write-ups:

Overhand: Simeon Woods Richardson

High Three-Quarter: Maddux Bruns

True Three-Quarter: Landon Roupp

Low Three-Quarter: Ricky Tiedemann

Sidearm: Carson Palmquist

Submarine: Tyler Rogers

Arm Action
Unlike arm angle, which describes where the ball is released, arm action describes the path the arm takes to reach that release point. It largely boils down to how far a pitcher’s throwing arm gets extended behind his body before he brings it up to his release point. For the most part, arm action is broken down into the obvious subcategories of “long” and “short,” with a ton of “medium” filling in the gaps between those two extremes.

Some pitchers reach back and straighten their arm downward before bringing it up, as illustrated here:

Long: Griff McGarry

While Griff McGarry’s arm is nearly straight at its lowest point during his windup, pitchers with shorter arm actions keep their arms bent behind their upper body, with their wrist never reaching below their chest, as seen here:

Short: Lucas Giolito

Lucas Giolito is something of a poster boy for this type of arm action. While he was struggling to realize his potential as a top pitching prospect, Giolito found great success in shortening up his arm action. It’s usually most notable when a pitcher’s arm action falls on one end of that spectrum or the other, and it’s often easy to spot when a player undergoes a mechanical adjustment that takes him to the other end of the spectrum, like Giolito did. But lest shortening up be seen as a magic bullet for fixing command or injury prone-ness, it should be noted that other pitchers have made similar adjustments without seeing the same stellar results. For example, A.J. Alexy has undergone a similar adjustment to Giolito’s, but while the shortened arm action provided a road map to Cy Young contention for Giolito, Alexy’s struggles are still ongoing.

Shortened Over Time: A.J. Alexy

Drop-and-Drive vs. Tall-and-Fall
These terms refer to how much power a pitcher generates from his lower body.

A drop-and-drive delivery refers to one where the pitcher uses his lower body to create much of the power by pushing hard off the rubber with his back leg. This can also be referred to as “getting into his legs.” It’s characterized by a deep leg bend, followed by a long, powerful stride toward the mound as a way to supplement what his upper body is doing.

Drop-and-Drive: Xzavion Curry

As the video shows, Xzavion Curry’s back leg is at an almost 90 degree angle when he starts his momentum toward the plate.

Conversely, a tall-and-fall delivery is exactly what it sounds like: The pitcher maintains vertical length throughout his delivery, and barely bends his back leg at all, instead relying on his height and gravity to enhance the power created by his upper body. It’s no surprise that this is most obvious when describing an especially tall pitcher.

Tall-and-Fall: Sean Hjelle

As you can see, Sean Hjelle hardly bends his back leg at all as he moves toward the plate, painting a stark contrast to someone like Curry.

Repeatable Delivery
One thing that comes up a lot when describing a prospect is how repeatable or “smooth” his mechanics are. No matter what mechanics are employed, pitching is inherently hard on the human body. But smoothness and repeatability are seen as ways to help mitigate the damage pitching does to the body, and they bolster confidence that the results a pitcher gets with his mechanics will be sustainable as he continues to develop.

Repeatable Delivery: Owen Murphy

The above video shows three consecutive pitches that Owen Murphy threw during a game in 2023. His mechanics are virtually identical in all three instances, to the point that an overlay of these three pitches reveals virtually no deviation in his mechanics.

Murphy’s body type is relatively compact, which makes it easier for him to maintain this repeatability and smoothness. It’s more impressive when a tall, lanky pitcher is able to do this, which is one of the reasons why Eury Perez was so highly touted as a prospect.

Repeatable Delivery: Eury Perez

Violent Delivery
Whereas a repeatable delivery is one that helps mitigate the physical stress pitching puts on the body, a violent delivery is one that fails to do so, or perhaps even exacerbates these stresses. The term “violent” is a tricky one to define, as it can mean any number of deviations from traditional mechanics that create added physical stress. And while it can inspire concerns regarding a player’s durability, the “violence” in a delivery is often what creates top-level velocities, which means it may not always be something that a player is aiming to do away with entirely. It is also something of an umbrella term, so illustrating it with video is not easy; the below examples are not comprehensive, and may be added to in subsequent installments of this series.

There are many factors that could result in a pitcher’s delivery being deemed “violent.” Here are just a few examples:

Flailing Limbs: Hans Crouse

It’s not hard to understand why Hans Crouse’s delivery is described as violent. His limbs flail and his head bobbles about, and very little of his mechanical approach is anywhere close to repeatable. In fact, here is an overlay of two back-to-back pitches he threw last season:

As you can see, it’s a far cry from the repeatability of Murphy or Perez.

Head Whack: Cole Henry

Head whack is another term you’ll often see used when describing the violence in a pitcher’s delivery. It’s a relatively easy thing to spot and is exactly what it sounds like: the pitcher’s head moves abruptly as he throws the ball. In Cole Henry’s case, it’s so extreme his hat often falls off his head during his delivery.

Cross-Body Delivery: Freddy Peralta

A cross-body delivery can be valuable to a pitcher, in that it adds deception that makes it difficult for hitters to pick up on the ball as the pitcher releases it. In Peralta’s case, he starts with his feet in the middle of the rubber, but his front foot lands well toward the third base side of the mound, in a way that hides the ball effectively but adds stress to his upper body as his arm whips across his torso.

Arm Timing: Mason Miller

Some types of violence in pitching deliveries are harder to spot. Typically, violence refers to the way a pitcher’s body moves after his front foot lands, and what type of stress those movements put on his body. In Mason Miller’s case, it largely comes down to how he times his arm with the rest of his body.

When his foot lands, the forearm of his pitching arm isn’t yet parallel with the ground below him, with his wrist still noticeably lower than his elbow. This requires him to create late, explosive arm speed in a way that has to be very hard on his joints, with some scouts pointing to it as the reason why he’s had trouble staying healthy.

Stiff Lower Body: Reese Olson

At foot-strike, Reese Olson’s arm isn’t dipping below parallel like Miller’s, but his stiff lower half requires him to compensate by generating virtually all of his power using his upper body in order to reach his typical mid-90s fastball velocity. This adds stress to his upper half, and causes concerns regarding the likelihood that he’ll be plauged with injuries in a similar way to Miller.

Hip/Shoulder Separation: Jairo Iriarte

The violence in Jairo Iriarte’s delivery has to do with his hip/shoulder separation, which is ostensibly a good thing, as it’s what generates the torque that allows him to hit the upper 90s with his fastball. When his foot lands, his hips are square to the plate, but his chest is still facing the shortstop in a way that seems impossible when it’s isolated in a freeze-frame, but which is likely a necessary element to his success.

It’s hard to say that the various types of violence in Miller, Olson, or Iriarte’s respective deliveries should be removed entirely, as they are likely significant contributors to their top-end velocities. Instead, we tend to see violence as a reason a pitcher may end up being better suited for a high-impact relief role rather than the starting rotation, so as to mitigate the violence in their deliveries by way of requiring fewer in-game reps.

That’ll do it for today’s introduction to our video glossary. I hope it helped to illuminate the meaning of the words we use to make these types of oranges-to-oranges player comparisons. Of course, this barely scratches the surface of pitching terminology, let alone the language used to describe hitting. Keep an eye out for future installments, with more definitions and helpful GIFs to aid in your enjoyment and understanding of the countless scouting reports to come.

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