Say you have an athletic child in middle school: Specializing in which sport in high school would make it most likely for your son or daughter to earn a college scholarship? The new self-help book from data scientist Seth Stephens-Davidowitz, Don’t Trust Your Gut: Using Data to Get What You Really Want in Life, which attempts to be “Moneyball for your life,” crunches the numbers on this and other intriguing topics.
The first question is whether your child has any particular genetic blessing from nature. Or would your scion have to make it on specialized nurture alone? For example, if your son is on track to grow to be more than seven feet tall, then basketball is of course a good bet: About one in seven of the tiny number of American men over seven feet make it to the NBA.
Stephens-Davidowitz has a clever way to estimate how genetically determined success is in different sports: What proportion of siblings at the highest level are identical twins? For example, the NBA has had ten pairs of twins in its history, with at least nine pairs being identical. Of all the fraternal twosomes in NBA history, 11.5 percent have been identical twins, a very high fraction. If one identical twin is good enough to make the NBA, it appears the other has over a 50 percent chance of making it too. The author guesstimates that genes determine 75 percent of basketball success.
Not surprisingly, considering how dependent basketball success is upon height, which these days is overwhelmingly genetic in origin, that makes basketball one of the four sports where genes matter most.
The most genetically influenced sport is track and field, where an astonishing 22.4 percent of all Olympic same-sex siblings have been identical twins.
Next are wrestlers, where 13.8 percent of Olympic brothers have been monozygotic twins, followed by 12.4 percent of rowers, such as the 2008 Olympian Winklevoss twins who are jointly played by Armie Hammer in the movie The Social Network. When considering suing Mark Zuckerberg for stealing their idea for what became Facebook, one suggests giving the Zuck an old-fashioned thrashing instead. After all, he reasons, “I’m 6′ 5″, 220 pounds, and there’s two of me!”
In contrast to twin-rich basketball, only 1.9% of major league baseball brothers have been identical twins. An identical twin of an MLB player has only a 14 percent chance of making the big time. According to Don’t Trust Your Gut, baseball skill is only about 25 percent genetic.
The latest baseball twins (and the first since Jose and Ozzie Canseco in the early 1990s) are relief pitchers Taylor and Tyler Rogers. Oddly, while Taylor is a conventional power-pitching lefty with a 96-mile-per-hour sinker, soft-throwing righty Tyler only made it to The Show by learning how to pitch submarine-style. His fastball averages merely 83 mph, but he has a weird slider that breaks up rather than down. Evidently, even identical twins aren’t always terribly similar.
My guess is that while pitching potential is fairly genetic, pitching accomplishment is highly contingent on random arm injuries. Perhaps almost every one of the 150 or so starting pitchers in the big leagues could have an All-Star season if he were perfectly healthy during a year in which he’s also got his delivery mechanics and his mental state straightened out.