“Man selects only for his own good: Nature only for that of the being which she tends.”
—Charles Darwin, The Origin of Species

The question of short starting pitchers is one that has always interested me, ever since Kevin Goldstein (#RIP) asked about it broadly on these pages way back in 2008. Does a pitcher’s height really matter in regard to his ability to get hitters out, particularly through multiple turns of a lineup? Is being tall an evolutionary predisposition for successful starting pitching?

First and foremost, it’s probably helpful to confirm that starting pitchers are, in fact, a taller breed. And they are! Unequivocally and consistently. Bearing in mind that the average adult man in the United States stands just under 70 inches tall, here are the average heights of qualified starting pitchers in each of the past five years:


# Qualified SP

Average Height
















Compare this with an average reliever, who over the same span stood an average of 74.36 inches—it’s not a ton of variance, but it exists, and it exists consistently, year in and out: an average relief pitcher is shorter than his starting counterpart.

So, then, what gives? Why is that? And why are pitchers of all stripes taller than the average bear? I though back about that KG (#RIP) piece, and a recurring argument in the comments stuck out. Here’s the most succinct version of it:

Brian Kopec


"There very well may be a bias against short pitchers at the professional level, however I think the bias at the amateur level has much greater impact on the number of short pitchers we see at the professional/major league level. How many hard throwing 'short' 14 year olds, showing up for their first day of high school practice, get a chance to develop on the mound? It's more likely that they are ushered to the middle infield (assuming they are athletic) or given shin-guards and a mask."

Interesting! Intrigued, I posed some open-ended questions about pitcher height to the rest of the prospect team on our Slack. Jeffrey Paternostro independently raised this very same theory, floating that “there is probably something to the idea that we select for pitchers even earlier than the pro ranks.” Pitchers in youth baseball, he went on to explain, tend to be the most athletic, coordinated players just by virtue of the physical demands of the act. So the shorter ones are more likely to move off to a premium position on the defensive spectrum, where, in turn, they’re more likely to gain their footholds that springboard them into the pro ranks. “If you’re a tall guy who throws hard,” he noted, “it’s right field or first base” for you when you’re not on the mound, and “if you have actual draft hopes, first base or a corner outfield is not ideal” (see Pratto, Nick in the current draft class).

Then again, the preference for taller starting pitchers may be bigger than any of these individual factors. “This isn't just a baseball thing,” argued Mark Anderson. “Taller is generally a societal preference in most arenas, and that's been born out through evolution and the progression of civilizations. As much as there is some inherent bias for taller pitchers in baseball, [it’s unclear] if the preference occurs at any greater rate than in the rest of humanity.”

Tabling the societal implications for another time (preferably with more whiskey handy), there are also the theories of plane and hitter perception at play here. There was agreement on the prospect team that evaluators tend to privilege plane as an asset for starting pitching prospects. The way we talk about it in Eyewitness Accounts tends to carry inherently positive implications. We know that “downhill plane” does indeed exist as a thing, because angles exist. What is less clear, however, is whether steeper angles really do produce a net advantage for taller pitchers, or at least the ones with the tallest release points.

The data here is tepid. Carson Cistulli ran a quick-and-dirty study of ground-ball rates as they correlate to pitcher height back in 2012, and he found out that, well, they really don’t. I had Harry Pavlidis crunch the numbers for the subsequent and most-recent five-year range for good measure, and based off 15 combined years of data we can pretty safely say that there’s nothing to see here: As a class, tall pitchers are no better at generating ground-balls than shorter pitchers.

The effective velocity argument, however, is still an interesting one. Thanks to all sorts of fun new toys, we now can do wondrous things in terms of measuring the difference between real and perceived velocity. We’ve known for a while now that extension to a point of release out in front of the pitching rubber can have a direct impact on the speed of a pitch as the batter sees it. We’ve seen how this effect plays out, and it’s not pretty for hitters. The closer a pitcher’s hand is to the plate at the point of release, the less time the hitter will have to make up his mind about whether or not to swing. And, at least in theory, taller pitchers with longer limbs can extend farther out from the rubber to deliver their pitches.

The problem with this as it relates to broad-based generalizations is that, as with most things we generalize about, the causes and effects of perceived velocity differ from pitcher to pitcher. “Effective and perceived velocity is case-by-case,” warned Steve Givarz. Taller pitches “can ride down the mound better in theory, but so many of them have poor extension.” This is a key point: just because a pitch is thrown by a tall guy does not mean that a batter can automatically gird his loins for outsized perceived velocity.

So where does all of this leave us with regard to pitcher height and efficacy? Perhaps most importantly, it leaves us with the specter of unnatural selection afoot. Back in 2010, Glenn P. Greenberg published a deliciously in-depth study in the Fall Baseball Research Journal for SABR about pitcher height and likelihood of effectiveness. The study is a worthwhile cover-to-cover read, but he found that, despite the best efforts of the scouting and front office communities, there just wasn’t any evidence that shorter pitchers made for worse or less durable starting pitchers than taller guys.

Kyle Boddy went even deeper on this subject, arguing this past summer that the tendency for evaluators to conflate height with durability is further problematic from a kinematic standpoint. “From a purely mechanical look at pitching,” he concluded, “the taller pitcher not only has the potential to have worse command problems due to the length of the forearm (not to mention the humerus), but also has a higher multiplier for torque and therefore stress on the structures of the human body.”

“Stuff,” Steve declared, presumably in his finest Goldblumian tenor, “finds a way.” Marcus Stroman can attest to that. But it sure seems like the surviving pool of professional pitchers isn’t necessarily the fittest, and within that structure there remains an undue tax on the evaluation of shorter pitchers.

So, armed (eh?) now with our realizations about what may just be a faulty general bias against short pitching prospects, let’s turn our attention to some arms who may get unduly dinged for their vertical challenges and therefore make for solid value targets in dynasty formats.

Francis Martes (RHP)—Houston Astros (Triple-A Fresno)

Martes is perhaps an exception to the value component of this discussion, rated as he typically is among the elite pitching prospects. But as a hurler whose listed height of 6-foot-1 might be on the…optimistic side, and whose round, compact frame has drawn some derision as a challenge to his prospective durability, he fits the bill as a guy who probably draws a shade too much skepticism given his athleticism and body control. He throws what remains one of the best curveballs I’ve seen live, and for my money is as no-bones-about-it a frontline pitching prospect as you’ll find. For a second straight year he’s come out of the gate relatively slowly, with some early command issues leading to an ugly, even-up K:BB rate. He had his start skipped this week on account of a minor abdominal strain, and the combination could just provide you with your last window of opportunity to acquire him for a marginal discount before he storms the Houston gates later this summer.

Carson Fulmer (RHP)—Chicago White Sox (Triple-A Charlotte)

Fulmer’s undersized frame and high-octane delivery were the subject of immense pre-draft scrutiny in 2015, when the stuff and performance suggested a potential top-overall pick, but those concerns weighed heavily in ultimately bumping him down the ladder a couple rungs to the No. 8 pick. It’s been a mixed bag for Fulmer since signing, as he fast-tracked all of the way to a big-league debut last year despite a mediocre run of production in the high minors. The questions about his landing spot have as much to do with his tempo and violence on the back end of the delivery as they do his stature, though narratives certainly don’t help his cause. The walk rate is down thus far at Triple A, but so is the strikeout rate. The interplay between those two over the next couple of months should tell us how much potential for second-half value there’s going to be here, and re-drafters would be wise to take note.

Justus Sheffield (LHP)—New York Yankees (Double-A Trenton)

Chaz Fiorino just wrote up Sheffield in a recent Notes From the Field, so I’ll refer you to that for the most current goods on the youngest pitcher in the Eastern League. He’s another shorter pitcher who does well to offset his height with extension, and athletic lefties with heaters into the mid-90s tend to find big-league work, so despite whatever warts (just and unjust alike), there’s a higher-probability of some form of return on investment in medium-depth leagues.

Andrew Moore (RHP)—Seattle Mariners (Double-A Arkansas)

Moore’s been dinged for his size since his days of dominating for Oregon State, and the scrutiny only intensified after Seattle popped him in the competitive balance round in 2015. He throws fringy spin to boot, so the margin for error here is not the biggest. Fortunately for Moore, he’s been able to survive and thrive thanks to outstanding command of a fastball that gets on guys quickly thanks to his tall, out-front release point and high spin rate. An excellent changeup plays off the same line and arm speed, and his up-tempo pace has produced outstanding results at every professional stop, including nearly 140 Double-A innings now. He’s certainly not the sexiest pitching prospect to target even in medium-depth leagues, but in leagues with 16-plus teams his future kind of steady back-end production should hold plenty of appeal.

Sixto Sanchez (RHP)—Philadelphia Phillies (Low-A Lakewood)

I’m contractually obligated to lower the tone of my voice when speaking Sixto’s name, and don’t think for a second that Paternostro’s ears didn’t just spike when he heard even the muted tones. Sanchez is 18 and a whopping four starts into his full-season career, yet there are already signs of in-progress breakout here, which Jarrett Seidler touched on in an excellent piece a couple of weeks ago. The 20-year-old Dominican does his work with premium arm speed that helps him generate plus-plus velocity, albeit with some requisite shorter-guy effort. The athleticism and, in turn, command profile here is what really stands out for such a precocious arm with such big stuff. If you’re looking for a helium candidate in the early going, Sixto’s a fine candidate—and one who might come a little cheaper right now than he otherwise should as a smaller-framed hurler.

Freddy Peralta (RHP)—Milwaukee Brewers (High-A Carolina)

Standing 5-foot-11, Peralta is an interesting case, as in spite of a low three-quarter, crossfire delivery he has managed to generate the best out-front extension of any “undersized” (read: less than 6-foot-2) starter in all of minor league baseball this year. The release point helps a fastball with already nasty arm-side run in the low-90s play up that much further, and it gives cover to secondaries that, while they flash utility, still have a ways to go with their consistency. After struggling in his first taste of High A last summer, the 20-year-old’s first five starts this spring have yielded excellent results, with 35 whiffs and a .185 average-against across 23 innings. His size and delivery play into conventional wisdom assumptions about a bullpen future, but there’s a legitimate three-pitch starter’s kit here.

Marcos Diplan (RHP)—Milwaukee Brewers (High-A Carolina)

If you’re sensing a theme here about the Brewers’ High-A rotation, you’re not alone—and you can toss a third rotation-mate, Jordan Yamamoto, onto the pile of shorter righties with the highest extension rates in the minors. Diplan is perhaps the most heralded of the three, able as he is to bump 94 with a slider that’ll flash plus. Craig vetoed his inclusion in our Milwaukee Top 10 list this past winter, but it was a close call, and given that Diplan will pitch all of 2017 as a 20-year-old in High A he’ll have ample opportunity to hold his own and force the issue by this time next year.

Vladimir Gutierrez (RHP)—Cincinnati Reds (High-A Daytona)

I touched on Gutierrez in a ”Minor League Update” a week ago, noting that the Reds’ seven-figure investment had looked the part thus far in his stateside debut. He’s got some Tiante in him, with a closed-off front side, through his leg kick, followed by a massive stride that gets him farther downhill than his modest 6-foot frame should be expected to get. There’s danger of over-extension and unintended elevation from his motion, but while he has indeed yielded some hits with loose command in the zone thus far, his control’s been solid and he’s been missing bats. Keep an eye on this one.

J.B. Bukauskas (RHP)—University of North Carolina

Bukauskas is today where Carson Fulmer was two years ago, as a dominant major-conference ace who has done just about all he can do in his draft spring, but who might slip down below another college arm or two on draft boards thanks in large part to his maxed-out 5-foot-11 frame. Regardless, he’ll be one of the first pitchers in this draft class—if not the first—taken in summertime dynasty drafts, insofar as any other leagues besides my dorky home league have one of those.

Logan Allen (LHP)—University High School (FL)

Allen is, per our own Steve Givarz, one of the two best prep left-handers in Florida, which puts him high up on the short list of prep left-handers in the country. At 5-foot-11 and without a ton of physical projection beyond that, he’s a quintessentially dinged-for-being-short guy. Steve wrote him up about a month ago, and he’ll warrant deep-league attention as an perhaps unheralded pick-up opportunity for those in leagues without player universe restrictions.

Floral arrangements of appreciation to Rob McQuown, Ben Lindbergh, and Justin Perline for data assists.

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I don't know about your experience, but in my youth coaches put arms at short and 3B. I even played SS as a lefty because I was the kid that could make an on-target throw to first reliably (pitcher was taken already). I think that in my day coaches thought a kid making the throw to second or home to record an out was something of a fantasy.
I think there is an underlying logic flaw in your discounting that "taller pitchers don't actually generate perceived plane that creates more ground balls". When looking at the "end result of natural selection" sample of "MLB pitchers", there is no difference in ground ball rates. But -- those are only the pitchers that have survived massive natural selection. At the margin, these survivors are (more or less) equally successful. But -- that doesn't mean that being tall intrinsically doesn't have massive advantages on perceived plan / ability to get ground balls.
With regard to ground balls, it's not a question of perception, it's a question of results, right? And in the data we have, there's just not any evidence of a correlation between pitcher height and ground ball rate. That's partially due, I think, to the facts that 1) taller pitchers don't generate inherently greater plane (as I discussed, that's a product of arm slot and extension in addition to raw height) and 2) angle of attack may not be as singularly important as something like late movement vis-a-vis getting under barrels. Particularly *because* the end result of selection leaves us with a sample skewed towards taller pitchers, the evidence of a correlation between raw height and ground ball rate should show up in that end-game data if there is one, and it doesn't.
I don't think you are understanding his comment. He is simply saying that if GB rate is indeed correlated with height we may not be able to tell at the MLB level because everyone who makes it to that level is able to induce a certain minimum GB%. It could be that only 1% of all short pitchers make it to MLB because or pro baseball because most of them can't throw enough GB and 10% of all tall pitchers because many more can throw GB. That's what he is saying.

That applies to many things at higher levels. You cannot necessarily see correlations and spreads of talent by the time you get to the major league level because everyone who makes it to that level has some minimum level of talent. BABIP is a good example. One of the reasons why we see such a small spread of talent wrt BABIP among major league pitchers is because the ones who don't have a certain minimum level of BABIP talent get weeded out.

So just because we don't see a strong (or any to speak of) correlation between some trait and some result (like height and GB rate) in sports doesn't mean that there isn't a strong correlation long before the player gets to the professional or top of the professional rank.

In fact, it is likely that we DON'T see much correlation between height and pitcher effectiveness at the major league level even if there is a strong correlation at the amateur level. Only the very best shorter pitchers will ever make it to the majors. Many more taller ones will make it, percentage-wise.

How many 5 foot 8 pitchers do you think can throw hard enough to make it in professional baseball? I guarantee not many. But the ones that do, think Pedro, are going to be the very best 5 foot 8 pitchers in the world. You won't find much of a difference at the major league level between a 5 foot 8 pitcher and a 6 foot 5 one. In fact, the shorter one might be better on the average because if you can make it to the majors with that kind of height you're going to have to really impress a scout somewhere along the line. If you're a tall, lanky pitcher and can throw 85 or 90 mph you will get a very long look and a long leash. 5' 7" and throwing 87? No shot.
Thanks as always for the extensive argumentation, MGL.

I understand the argument, I just don't believe I agree with it. We care about outs, and the pitchers who can get them - at every level. And pitchers who gets outs all kinds of different ways make it to the MLB level. We privilege strikeouts (obviously) and ground balls (for their efficiency and safety in generating those outs), but there is no "certain minimum GB%" that is a prerequisite for an MLB career, as you state. Your 1%/10% figures are drawn out of a hat, they're entirely theoretical. It "could be" that 20% of short pitchers are good at getting grounders, to 10% of tall pitchers, too. My point was that on account of current amateur scouting and coaching biases, we have no way at all of knowing what those figures are, or rather would be without those biases.

My point was also to piggyback off Steve's comment in the piece, that being tall doesn't necessarily correlate with higher/lengthier release points, better perceived velocity, higher spin rates, or deadlier pitch movement. All of those things factor into ground ball - and, broadly, contact - rates. Taller pitchers aren't uniquely skilled as a class at leveraging their height advantage and translating it into better angles of attack, nor does a given tall pitcher's arm action and stride length result in inherently better extension. Those are case-by-case situations particular to every pitcher's unique mechanics and physicality.

Your last paragraph gets at the essential thesis of this piece: scouts *do* give that extra leash to the tall, lanky pitcher, yet the sum of available data suggests they aren't necessarily right to do so.
GB% is a bad example of the kind of selective process I was discussing because it is NOT a trait that is particularly correlated with success at any level. However, my point still stands. By the time you get to the professional and especially the MLB level, the spread in talent for most things has considerably narrowed to the point where it can be difficult to identify that spread. So I don't really know what you are disagreeing with.
I'm curious about y'all's take on Carl Edwards Jr. I know the Cubs seem dead set on him being their version of Dellin Betances but he seems like a poster child for this kind of bias. I know he had a mysterious shoulder injury in 2014 that kept him out for a while but his numbers as a starter before (and briefly after) were outstanding. Plus, he'd already reached the 100 inning mark the year prior without issue and with ridiculous numbers (66 cfip!).

The only problem is that he's 6'3" - not far off from the median heights listed for starters. Is it the 170 lbs? Is there something about his repertoire I'm not aware of? Or are the Cubs just blessed with so much SP depth (well...) that they can have someone of this caliber languish in middle relief (doesn't explain the last couple years of development though).
Has anyone studied height differentials between position players and pitchers over time? My impression from looking at old team photos is that the pitchers were always the tallest guys in the back row.