According to this article by Greg Spira in Slate, one thing many American ballplayers have in common is that their parents liked knockin’ da boots in December — which by simple addition means they were born in August.
In fact, far more American-born Major League Baseball players were born in August than any other month. The month with the fewest players? July.
The statistical distribution indicates that the traditional July 31 cutoff for Little League ages played a large role in launching the careers of budding baseball stars. Kids born August 1 are typically the oldest — and therefore biggest — kids on their teams. Kids born in late July are the puny lickspittles that have trouble lifting their bats:
Twelve full months of development makes a huge difference for an 11- or 12-year-old. The player who is 12 months older will, on average, be bigger, stronger, and more coordinated than his younger counterpart, not to mention more experienced. And those bigger, better players are the ones given opportunities for further advancement. Other players, who are just as skilled for their age, are less likely to be given those same opportunities simply because of when they were born. Alex Rodriguez would’ve been a star no matter his birth month, but a player like Juan Pierre, who has less natural aptitude for the sport, might have gotten a small leg up over similarly skilled players because he’s an August baby. It’s clear from the chart above that this small advantage can have an impact that lasts a lifetime.
I love the gratuitous slap at Juan Pierre. He sucks.
If you’re wondering if the distribution is coincidence or tracks with national birth statistics, Spira says the relative uniformity of birth month distribution in the NBA and NFL indicates that the variable is more important in baseball:
The relative age effect might not be prevalent in the NFL and the NBA because size is a bigger factor in those two sports than in baseball and hockey. Since an athlete’s ultimate height and weight aren’t clear until fairly late in his youth, league cutoff dates aren’t as important in determining one’s athletic destiny. Another possibility is that (men’s) basketball and football are much more popular high-school sports than baseball is. Since the cutoff date for high-school sports is more variable than that for organized youth sports, the influence of birth month in youth basketball and football leagues is relatively minor.
It should be noted that most youth baseball leagues have changed the cutoff date to April 1 or May 1, in order to square the age of the player more consistently with the baseball season. Which means the optimal time for Pax Arcana and the fleet-footed and fast-thinking Mrs. Pax Arcana to conceive the six-tool player of the future (Name: Cadillac — Sixth tool: Intimidation) would be August. So, um, don’t expect a lot of blogging in August.
The Boys of Late Summer [Slate]