why most athletes are born in January

This Christmas I want to (late) present you with a hashtag#pattern that I find peculiar and fascinating.

Last Thursday I had planned to go watch a top-tier European hashtag#basketball match between Real Madrid and CSKA Moscow, the most winning teams in the history of the sport. Lately I dusted off my passion for basketball and I am quite a regular at the arena. Sad story, due to the new raise in hashtag#Covid19 cases here in Spain I eventually decided to be cautious and watch it on TV. I think it was a good decision. Indeed, Covid hit and on match day I found out that it claimed many victims in the team of Real Madrid (7 players + coach). As a result, they were going to play with four youngsters, 3 of which were at their debut. While commentators focused on their year of birth (’03, ’04, ’04, ’04), after reading ‘Outliers’ by Malcolm Gladwell I couldn’t help but notice the months: Mar, Feb, Feb, May. All of them in the first half of the year, but four is not a valid sample. Few hours later, I didn’t resist the urge to scrape some data and check the month of birth for all “young” players (aged 24 or less) that get to the pinnacle of this sport in Europe: the hashtag#Euroleague. What I got (cheers Plotly) is what you see: to me, a weirdly beautiful pattern hidden in a piece of data that we all tend to assume it doesn’t capture anything. The number of players is inversely proportional to the month of birth, and only 1 player out of 10 is born in the last trimester! All Real Madrid young players but one are born between Jan and Jun. What does it mean? Apparently, most of this trend comes from the fact that the vast majority of youth sport associations divide players by year of birth, so that a kid born in December gets “unfairly” paired with one kid born in January who is 12 months ahead in his growth and development (the younger the age, the more it shows). Therefore, older, stronger kids overshadow the greener ones and get more playing time, go higher in the ranks and ultimately get more and better chances.

Now you know it. You can thank me for this when your son born in the last trimester becomes the next big thing in sports…