Derick E. Hingle/USA TODAY Sports

This story is an online exclusive from ESPN The Magazine's Nov. 28 Tall Ball Issue. Subscribe today!

IN HINDSIGHT, Anthony Davis' adolescence was like a science experiment: What happens if you hold skills constant while increasing height?

Back in the fall of 2008, Davis was a pretty good 6-foot-2 sophomore guard on a pretty bad Perspectives Charter School team in Chicago. He already towered over his mom, and was eye-to-eye with his dad, so Davis figured he was done growing. Cleveland State was the only college giving him a look.

By the following spring he was 6-8, and, as his high school coach put it, "He could still do everything -- pass, shoot, dribble -- he did before. He was just a lot taller." Anthony Sr. bought his son an extralong bed to accommodate his size-14 feet, which had been hanging off the end, while Junior swapped out Allen Iverson as his role model in favor of the Kevins, Durant and Garnett. After his growth spurt, he played one-half of one game in a summer tournament in Virginia and returned home to more scholarship offers than he could read. Two more inches later, he was the top pick in the NBA draft.

Davis is living proof of the difference half-a-foot makes -- particularly in today's game, which, like Davis, has grown. The average height is up more than 4 inches since the NBA's inaugural season 70 years ago, even if it is down an inch from the all-time peak of nearly 6-8 in 2001. While the search for bigger and bigger ballers seems to have leveled out (for now), the history of height makes it clear: Whether it's through international scouting or sci-fi-like technologies, the game will find a way to grow.

IN THE 1930s, sportswriters, lacking even rudimentary metrics, explained the glut of Jewish basketball stars as a result of diminutive stature that made for quick feet and deft balance (along with "general smart aleckness," as one journalist put it). Last year's record-setting Warriors squad confirms that the value of agility -- and perhaps general smart aleckness -- has been transmitted intact to the current generation, it's just that they're a lot taller (Steph and the gang last year had the NBA's 15th-tallest starting five at 79.4 inches). Like a young adult emerging from adolescence, basketball managed to get bigger and more gainly at the same time.

Pro hoops isn't alone. As most sports become more competitive, their athletes tend to grow. The rest of us have too, though not as rapidly. For much of the 20th century, the industrialized world grew about 0.4 inches per decade (the average American woman is now as tall as the average 17th-century Frenchman). The primary cause is likely nutrition. In Japan's post-World War II "economic miracle" period, the average height of men increased by 1.7 inches in 20 years, and of women by an inch. In societies where a particular group is nutritionally disadvantaged, inequity leaves a trace in stature. Black American men gained on white American men in recent generations, but are still slightly shorter. Prosperous areas of northern Europe have grown the most; the average Dutchman is now 6 feet. Nutrition, though, hasn't been the only driver of height. A study of 94,500 Dutch citizens over 30 years showed that part of the rise in height was due to more big dudes making the All-Star Procreation Team; yes, tall men average more children than smaller men.

Inevitably, sports officials have sought to turn humanity's skyward stretch into a competitive advantage. Before the 2012 London Olympics, Great Britain put generations of European growth to use with a clarion call for tall women. Their "Sporting Giants" program was sort of like "Britain's Got Talent," but for wannabe athletes. One auditioner was a rangy teacher-in-training named Helen Glover. At a tryout, she rowed for the first time in her life. That was eight years ago, and Glover is undefeated for the past five of them, including two Olympic gold medals and a world record. China has been more systematic still. Yao Ming was spawned from China's tallest dyad, a pair of ex-basketball players coupled by the Chinese basketball federation.

Genetics can be telling: A Wall Street Journal study found that nearly half of NBA players have an elite-athlete relative, while fewer than one-fifth of players in the less height-dependent NFL and MLB do. Of the dozens of pairs of NBA brothers, there are a few guards -- like Steph and Seth Curry -- but more frequent are sky-scraping siblings, like Mason and Miles Plumlee, Marc and Pau Gasol, and Brook and Robin Lopez.

That's why a study of a New York egg-donation clinic found that the proportion of customers asking for "athletic ability" in their eggs increased from 1 percent in 2008 to 17 percent in 2012. Surely, they demanded height. In the dropdown menu at the California Cryobank, height is the only physical trait you can sort sperm donors by. Over on the sidebar, you can search for "look-a-like" donors. There's just one Andrea Bargnani look-a-like, and -- given the rarity of 7-footers -- he's a mere 15 inches shorter, at 5-9. (But, ladies, he is a "natural born entrepreneur.")

The gift of ginormity is so terrifically precious because it is so exceedingly rare.

In the NBA, sky-scraping siblings like Brook and Robin Lopez aren't uncommon. AP Photo/Don Ryan

IN 2016, THE industrialized world seems to be past its growth spurt. Even the soaring Dutch are finally holding steady. So if we've nearly maxed out gains from nutrition, Tindering for tallness and Bargnani look-a-likes -- at least in the U.S. and Europe -- what's next? Artificial selection will continue in sports. Usain Bolt will prompt more lanky kids to realize their speed, while Kevin Durant will inspire tall teens to eschew the lane. And while rule and strategy changes friendly to 6-3 shrimps may lessen our dependence on foreign height, scouts continue to import inches -- the average height of foreign NBA players is 6-9, whereas it's a bit under 6-7 for Americans. As Americans and Europeans slow in their skyward stretch, scouts will look elsewhere: to a few billion residents of China and India, who have a growth spurt coming as their economies modernize.

Tim Olds, an Australian scientist who studies how sports body types change over time, says that already "we certainly see a lot of tall Chinese and Indian people in Australia." In China, men are 5-6 on average, and women 5-1.5. Move the average up just a touch, and the far right tail of the Chinese height curve makes for a whole lot more bigs. Round up every American man of viable NBA age who is at least LeBron James' height, and you could seat them all in Quicken Loans Arena. If China one day has the same average height as the U.S., the number of LeBron-sized men of NBA age would not fit in Quicken Loans; it would overflow the Cowboys' AT&T Stadium.

According to the Chinese Basketball Association, there are 300 million basketball players in China. As a group, that would be the fourth most populous country in the world, and -- despite China's greater success in diving and gymnastics -- basketball is the people's sport. Even when Chairman Mao Zedong waged war on parts of Western culture, he wanted every soldier to be able to sink a free throw. Young Chinese basketball players later idolized Michael Jordan -- Qiao Dan of the Red Oxen -- and Kobe Bryant. Take that fervor and transpose it onto a first-world height distribution, and we may one day laugh at the thought of Yao Ming as a rare basketball emissary from the Far East.

Could Yao Ming be the first of a glut of Chinese superstars? Jesse D. Garrabrant/NBAE via Getty Images

BUT WHAT IS the future of height at home? Are most of us doomed to get sized out of our sports? As someone who was regularly asked by a high school coach, "When are you gonna grow?" I'm quite sure that humans will avail themselves of technological means to reach for the heavens. Reports from India describe "height surgery," in which leg bones are broken and fitted with braces to elongate them. Earlier this year, an ethics committee in India convened surgeons to discuss the unregulated procedure after it was performed on a young man who was 5-7. Then there's human growth hormone. It's banned in all sports, but nobody minds that Lionel Messi used it as a child to attain normal adult height. One endocrinologist I spoke with mentioned a kid who took HGH because his parents were concerned about his size, and he became a 6-8 college basketball player. In 2008, Congress convened a hearing about increasing use of HGH, at which one of the expert witnesses told me that he regularly heard from parents wanting HGH for normal-height children. Mark Cuban recently funded a University of Michigan study on whether HGH can speed surgical recovery. If HGH goes mainstream -- it's already more widely used in Canada -- would you get it for your child?

If you could, would you even employ the cutting-edge gene-editing technology CRISPR, which allows scientists literally to customize genes -- a sort of unnatural selection? Perhaps fortunately, we have no clue what most genes do. Then again, maybe we don't have to. We know that a pituitary gland tumor causes overproduction of growth hormone. Gheorghe Muresan, the 7-7 former NBA player, famously had such a tumor removed after he was drafted. We also know of the GHRH (growth hormone-releasing hormone) gene, which is involved in signaling the pituitary to release growth hormone. Defects in that gene can cause dwarfism, or gigantism. So what if we could alter just that gene? Well, we can. The steady increase in height might be winding down in the U.S. -- but that's exactly why the next growth industry may be growth itself.