“They have crooked arms. They throw crooked, they walk crooked, and they think crooked. They even wear their clothes crooked. You have to figure they’re a little crazy.” —Al Schacht

“There ain’t a left-hander in the world who can run a straight line. It’s the gravitational pull on the earth’s axis that gets ’em.”Ray Miller

“Just because I’m left-handed and quotable doesn’t mean I’m from another solar system.”Joe Magrane

“I don't need them. Just being left-handed is like taking a greenie a day."Tug McGraw, on amphetamines

If you’re like me, you hadn’t left diapers far behind when you were first told that left-handers were a different breed—which is to say that I had that maxim drilled into me young, not that I proved particularly resistant to potty training. As with most aphorisms, there’s some truth to this one, since handedness is a hardwired physiological preference. Still, just as we often either consciously or unconsciously exaggerate the differences between people of different races and colors (or mistake learned differences for innate ones), we tend to read a bit more into this particular phenotypical quirk than the circumstances demand, regarding left-handedness not just as a physical characteristic, but as a personality trait.

In the interest of full disclosure, I am not now, nor have I ever been left-handed. Fortunately for those who are, the popular perception of their preference has evolved to the point that they’re now more likely to be deemed creative, artistic, or at worst, a bit goofy than unintelligent, clumsy, or outright evil. Still, despite inconclusive studies—or studies that suggest that any real behavioral disparity is the result of adapting to life in a right-handed world—some perception of otherness persists.

To be fair, baseball’s southpaws have done little to dispel that impression, in some cases going to great lengths to embrace eccentric personas. But it’s not just in an off-the-field sense that left-handed hurlers have distinguished themselves; they’ve also become known for doing more with less on the mound. To the quotes above, add a few more phrases uttered by too many mouths to attribute their origins to just one. Many a portsider has earned a backhanded compliment for “throwing hard for a lefty,” developed a reputation for being “crafty,” or spent his later years bearing the dismissive descriptor “Have left arm, will travel.” But do lefties actually throw any softer, or is that just another myth perpetrated by the right-handed majority?

While the sartorial tendencies observed by Schacht in the quote at the top of the page remain unproven, left-handed pitchers do tend to have less giddyup at their disposal than their right-handed cohorts. Here were the average velocities of fastballs (including cutters) thrown by full-time starters and relievers and captured by the PITCHf/x system from 2008-2009, broken down by handedness:











Okay, so we’ve established that there is something to this—a pitch can, in fact, be fast for a lefty when an identical delivery from a righty wouldn’t stand out from the pack. The logical next question is, “Why?” Like a lot of baseball questions that would seem to have simple solutions on the surface, this one turns out to be multilayered, but we can do away with at least one incorrect answer.

The Miller quote reproduced above may have been tongue-in-cheek, but it’s expressive of a prevailing attitude that has proven as difficult to eradicate as the notion that water drains in a different direction from toilet bowls in the southern hemisphere, a fallacy whose final debunking may have to wait for the first edition of Plumbing Prospectus. Judging by the responses of the few people I surveyed before embarking on this article, it's tempting to believe that some unseen force conspires to slow down southpaw deliveries, or that the mechanics of throwing from the left side are in some sense materially different from those of righties, rather than simply being reversed. The more one ponders that possibility, though, the more nonsensical it starts to seem, as the Magrane quote above suggests.

Whereas fledgling left-handed writers were routinely forced to write right-handed in less lefty-friendly times, it’s doubtful that any little-league coach ever tried to mold a righty out of a left-handed hurler. From 1993-2010, roughly 27% of major-league plate appearances came against left-handed pitchers; since only 10-15% of the general population is left-handed, it seems clear that pitching from the left side confers some advantage in baseball.

Some of the sport’s handedness advantages have to do with the way the field is structured; for example, left-handed first basemen have an easier time of throwing to other infield positions and facilitating pick-off attempts. Even left-handed pitchers get in on this act, enjoying more easily disguised moves to first and thereby limiting the opposition’s running game. On the other side of the diamond (and behind the plate), being right-handed is all the rage, again because of the angles involved.

However, that sort of institutional advantage isn’t responsible for the disproportionate percentage of junkballers who throw from the left side. In fact, those lower velocities can likely be chalked up to something as simple as the element of surprise. Since batters who aren’t strictly platooned face righties far more often than lefties, they simply aren’t as well-prepared to face the less familiar threat. As a result, some left-handed pitchers with lower velocity readings (and worse stuff overall) can ride that advantage—which has little to do with any actions on their part—to lengthy major-league careers, in the process depressing the average velocity for left-handers as a group. If right-handers were the less common brand, righties would be the ones lagging behind in radar-gun readings.

Obviously, it’s not as if being left-handed precludes a pitcher from throwing hard, or even cracking triple digits; if ever there were an exception that disproved the rule, it’s Aroldis Chapman. But since lefties have a built-in boost, they needn’t be as talented to achieve the same level of effectiveness (in turn, that makes lefties who are as talented especially desirable commodities, since they have no deficit in stuff to negate their “accidental” advantage).

The same lefty-favoring effect can be seen both in other sports and in the natural world; one can easily imagine how the same principle might apply to serving in tennis, among other activities, although the data necessary to determine whether that’s the case haven’t been made available. In addition, we can observe the same principle at work with some of baseball’s other mound minority groups; for example, submariners and knuckleballers get by with even less gas than left-handers. While it’s true that lefties aren’t nearly as rare as submariners and knuckleballers, as a group they possess significantly better stuff, which compensates for the fact that they’re found more frequently. Consequently, being left-handed won’t help you make the majors if your heater tops out in the 70s, but being Chad Bradford or Tim Wakefield will. Unfortunately, there are limits to the extent of left-handed powers; using your left hand to shine a laser pointer at your PowerPoint presentation won’t give you an edge in the boardroom.

The element of surprise enjoyed by left-handers manifests in more dramatic platoon splits; as a group, lefty batters take a bigger hit against same-handed pitchers than do their right-handed counterparts. The nitty-gritty of why platoon splits exist at all—in other words, the pitch types and movement that batters find more confounding coming from a same-handed pitcher—has been explored in some detail, but the question of why they’re bigger for lefty batters likely comes down to the same unfamiliarity we’ve already touched on—righty batters probably perform more effectively against same-handed pitchers simply because they receive more opportunities to do so.

There’s another possible explanation for the phenomenon: Lefties who can hit righties but not lefties can still find a job, but righties who can hit lefties but not righties usually don’t offer enough value to merit a major-league roster spot—unless, as Colin Wyers has observed, they’re named Jeff Francoeur, in which case all bets are off. In this scenario, we’re dealing with a selective sampling situation, wherein platoon-challenged right-handed hitters wash out before reaching the majors while their left-handed brethren continue to climb the ladder (more on that in an upcoming piece).

Either way, southpaw pitchers enjoy an advantage that has everything to do with their scarcity, and little to do with any of the quirks with which they’re typically credited. Lefty relievers enjoy that advantage even more often than lefty starters do, which helps to explain why they can succeed despite being even softer tossers in relation to their right-handed peers. As Mike Fast discovered last year, declining fastball speed affects lefties to the same degree as righties, so they aren’t immune to the ravages of time; it’s just that they’re fortunate enough to start out insulated by an extra inborn cushion.

Sometimes, all it takes to be considered crafty is a little lateralization of the brain. As it turns out, it’s not the proverbial right hand, but the batter who doesn’t know what the left hand is doing, and that’s the source of the southpaw pitcher’s advantage. Tug McGraw was right: Although players aren’t suspended when they test positive for left-handedness, they enjoy enhanced performance nonetheless.

Thanks to Mike Fast for research assistance.