Scouting a pitcher for the first time, like most one-game endeavors of evaluation, is a hard thing to do. You can almost always get a pretty good read on what the raw stuff is about, though even there you’ll run into some misrepresentations of a breaking ball’s bite or fail to pick up on a guy’s feel for the change if he’s just having one of those nights. But unless the player is injured or battling flu-like symptoms, you’ll be able to see what his current velocity and movement trajectories look like. And once you see how big he is and how he moves, you can usually extrapolate out a most-likely projection for his physical development.

But pitching is a science. There are countless, subtle manipulations of the body that a pitcher must undertake in particular sequence in order to get the ball to go where he wants it to go. Figuring out how consistently a pitcher is likely to execute his delivery over, and over, and over again…that can be awfully tough to ascertain in a limited sample. The slightest kink in the progression of a given wind-up—particularly early on—can set off a negative chain of events that throws off timing and compromises the pitcher’s command of the baseball. Maybe on the day you happen to see a guy for the first time he’s having some trouble breathing out of his left eyelid. Maybe he walks six guys in three innings. Or gives up six extra-base hits. Or all of those things. It happens.

What to do, then? What to look for? To try and protect against results-based evaluation I start by looking for balance and coordination. Control over one’s actions, one’s movements through space—these are the foundations of consistent timing. Pitching coaches are very big on consistent timing. Why is that, Mike Burns of the Lancaster JetHawks? “It's huge. The main part for me is getting [a pitcher’s] body to move fluidly and athletically. It’s easy for a lot of guys to get that stiff pitchers' delivery and fall into bad muscle memory. It's a matter of trying to get them to be an athlete, to move naturally. It comes down to the timing, and then from there they’re able to repeat.”

A player’s physicality will almost always shine through regardless of performance. Guru of pitching mechanics, Doug Thorburn, refers to this as each player’s “signature,” and it is the unique, natural progression for each pitcher’s delivery. It is, in other words, how his body wants to move. Guys who repeat well tend to do so because their bodies are moving in comfortable, organic progression. Guys who repeat better are able to hit their spots more consistently. And guys who hit their spots more consistently? Well, they’re big leaguers.

Different Cream, Same Crop

How to repeat? Broadly, there are two types of balancing acts: the first is a fluid delivery, which lacks much in the way of transition between “gears,” relying instead on a steady build of momentum from first move through release. Perhaps the most pertinent example of the best kind of extreme of this delivery is Corey Kluber.

Video courtesy of Steve Fiorindo

Kluber’s early momentum flows through a leg kick that never pauses, slows, or changes the direction of his energy; he calibrates himself quickly during his rock, his leg kick leverages the early energy into a rounded turn, and everything flows continuously downhill towards his target. It’s a one-piece delivery, and there is a gradual acceleration and fluidity from start to finish.

At the other end of the spectrum, some pitchers employ start-and-stop techniques that halt and store momentum before re-channeling it after the body sits on a defined balance point. The extreme of this is the best pitcher on the planet, Clayton Kershaw.

Video courtesy of Steve Fiorindo

Kershaw’s delivery is as unique as they come, with the near-stop gear change at the bottom of his leg kick – a relative rarity that not many pitchers share. The more common form of this delivery type, popular especially among Japanese pitchers, involves deceleration or even a complete stop in the initial phases of the delivery through the leg kick. Kershaw’s rotation-mate Kenta Maeda utilizes mechanics that are a good illustration of this:

Video courtesy of WBSC

Where the more fluid delivery is one in which the whole body is engaged and velocity comes courtesy of torque and rotation, this style of delivery gets all of its power from the lower half. Takashi Saito talked about this difference in contrasting American and Japanese pitching styles in an excellent 2009 piece on this cultural contrast by Alex Speier: “I pay really close attention to using my lower body well, feeling the ground, then transferring the power of my lower body through my core and keeping my balance throughout the process of pitching,” he explained.

Finding Your Cobb

Regardless of how a pitcher goes about it, he has to find his way to generating and directing force downhill in a consistent way. I talked to Rays reliever Chase Whitley recently, and he recalled a piece of instruction from his minor league days that has stuck with him ever since. “I had a coach in Triple-A who once told me that yes, we gotta get to those balance points, but we also gotta get that momentum generated toward the plate. It doesn’t matter if you get to a spot if you can’t generate any momentum going to the plate from it.” Balance points are all well and good, in other words, but it is most important to remember that they’re means and not ends.

How effectively a pitcher is able to store energy up through his backside and channel it downhill will determine a lot about both his power and repeatability. And there are different ideas about where that energy transfer should be centered. For Burns, the default is the inner thigh of the plant leg. “That inner thigh, up into the groin area,” he explains, “that's where a lot of guys are really best storing the torque that they build.” But it’s not a one-size situation, either. “You want to find a guy's athletic point where they're most effective in keeping balanced while generating the power that's going to get you down hill effectively.”

For other guys with different signatures, that can mean shifting the locus to the hips, buttocks, or outside of the back leg. Whitley credits teammate Alex Cobb’s own unique delivery for helping him understand that not all pitchers are necessarily alike when it comes to storing energy. “It makes sense for him what he does, but I can’t do that ridiculous leg lift that he has,” he laughs. “He does that to load up his glute, though, and I can’t necessarily get to that position where I’m loading up my glute like he does. I’m pitching more off my hamstring, and that back side of my leg. So when I’m getting to my balance position that’s what I’m thinking, and I want to get energy on the back side of my leg and inside of my foot as quickly as I can.”

Regardless of where each guy ends up locating his primary energy channel, maintaining balance on the back leg is a key to helping the lower half move naturally and freely. “The back foot will kind of do what it does as long as you engage the muscles back there the right way,” Burns notes. That’s important for the sake of pitch-to-pitch consistency, as forced movements or, worse yet, misplaced emphasis on the push off the rubber, can cause the delivery’s timing to go haywire. As Thorburn explains, “when you think too hard about ‘driving’ off the rubber it’s often easy to collapse the back leg, usually in an attempt to ‘push’ from the stripe. And this wrecks the foundation of balance.” Stability in creating energy generally lead to consistency in directing it.

Balance is not all

I saw Yaisel Sierra make three starts for Rancho Cucamonga before he ultimately converted to relief, then checked under a couch cushion and found a half-dozen sitting miles-per-hour on his fastball down the stretch, ultimately leading to a fairly successful Double-A promotion. Sierra displayed some of the most exquisite balance of any pitcher I saw this year:

He rolls onto the outside of his back foot a bit, creating an additional layer to sync up, but the lower-half momentum is fluid and consistent throughout. There’s an efficient flow of energy from the first move, and he flips it downhill very well from pitch to pitch. Yet his timing, particularly out of that half-wind, was highly erratic in each outing I saw. His arm path slipped and slid in different directions, his front side struggled to catch his powerful transfer of energy, and his timing in general was very poor to slot, leading often to elevated pitches that hitters tracked.

Meanwhile, on the other end of the spectrum there are guys like Seattle Mariners’ prospect Andrew Moore. While deception and a big stride both help Moore’s perceived velocity to play up above the radar gun, the raw stuff is more in the fringe-average range: high-80s up to low-90s from the right side, good changeup, struggles spinning the ball. He can command the hell out of it, though.

The seatbelt sign stays lit for that delivery. His spine and head tilt back enough towards centerfield that it creates ample opportunity for imbalance, particularly since he’s generating momentum very quickly from a near-stand-still start and aggressive leg kick. It’s a phenomenally repeatable delivery, however. Balance-wise Moore’s motion may not be one for the refrigerator, but he was as consistently on time to slot and as accurate with his full arsenal as anyone I saw all year.

These are cautionary tales about why it’s not a good idea to put too much stock into balance as an absolute determinant. Burns has seen plenty of athletic, balanced guys struggle to repeat, because there still has to be that timing and order between all of the moving parts. A pitcher can show consistency through his balance points, but then “the arm can still be inconsistent and just either drag, or because the guy’s late he's trying to fly open to get on time and he’ll yank a lot of balls.” And as Moore shows us, tails can come up just as often, with guys who manage to repeat less than ideally-balanced deliveries with great consistency.

We Do What We Can With What We Got

When evaluating and projecting players, there is an inherent danger in drawing automatic lines between Points A and B. “There is no ‘right’ or ‘wrong’,” Thorburn cautions, “because each pitcher has a different ideal. There is definitely a ‘right’ and ‘wrong’ for each pitcher's specific signature.” Broadly speaking, however, I tend to find that guys like Sierra and Moore are the exceptions to the more general rule. Balance may not be absolute as a predictive tool of evaluation, but it is a good indicator if a pitcher is working in sync with his natural physicality. It is, in other words, a symptom of underlying process, and a good way to tell if a guy’s command development has a higher ceiling, or whether it may take more time for the command to come together (if it ever comes at all).

The search for a pitcher’s given balance progression isn’t always a linear one, and that is perhaps the most important takeaway for evaluators. “I still struggle sometimes when I’m at the top of my delivery,” bemoans Whitley. “Trying to get everything going at the same time – I used to pause a little bit on my way down, and it just created some friction in my movements that led to erratic pitches.” It took him years, all the way up to his third season in the major leagues when he met Cobb, to really figure out how his body worked optimally within his delivery. Extrapolate that down to the low minors, and you quickly realize how far most pitchers have to go in order to develop big-league consistency.

The best we can do as scouts and evaluators, then, is to note the process for each player and project based on the best combination we can discern of individual physicality and broad likelihoods. For me, that means gravitating towards the guys with the best balance. Command your body, and you just may command the baseball.

Thank you for reading

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Very interesting article, thank you.
Very informative. Excellent stuff! Thank you.
This is really good stuff. Thanks.
How do you store momentum? Once you stop or slow down you lose momentum.You can momentarily store energy that will enhance your speed of movement if you properly utilize the stretch shortening cycle, but storing momentum is not part of that process.

You mention collapsing the rear leg. Probably need to define that better because a high % of the hardest throwers in baseball have significant flex in their rear leg. Chapman is a good example of that.

Finally the pitchers that are most consistent are the ones that can execute a pitch when they are not in sync, not the ones that are consistently in sync.Too many muscle fibers & nerve endings involved to think that their signatures are going to be consistent.
Thanks for reading and for your feedback!

Sure, "store the energy they create with early momentum," I can get down with that edit.

Doug brought up the rear leg collapse in his quote, and I used it solely in the context of repeatability and balance, not velocity generation. Without putting words in his mouth, I can say that broadly I think he argues, and I (again broadly) agree that drop-and-drive mechanics are more difficult to repeat. Lowering the gravitational center in-process adds extra degrees of difficulty; it's a trade off of potentially adding more velo (if your signature is compatible) versus making it more difficult to command. Again, not saying drop-and-drivers have inherently poor command, but that it's an extra set of hurdles. Some dudes are better at bridging that extra gap than others.

I'm just not sure I agree with your third point. A primary goal of the development process any pitcher goes through is creating rigorous enough muscle memory patterns that when he's "off" on a given pitch, he's off in ways that result in "good" misses. Pitchers can generally afford to get away with most reasonably narrow misses, because hitting is an absurdly difficult physical act. And there's obviously a sliding scale there based on stuff (velo, movement) and situation. But good command comes fundamentally out of consistent timing - how sync'ed you are at the point of release - and that's why I used this article to highlight what I see as a generally binding principle (that good balance is a helpful trait more often than not) among the individually unique processes involved in getting to slot on time pitch after pitch.