The book Outliers, written by Malcolm Gladwell, is an amazing read. Chapter 1 relates success in sports to which month you were born in. And the answer is fairly simple, although not always obvious. Most countries have cutoff dates for age-class sports. If you are a certain age, you make the cutoff. If you are not, you have to wait a whole year in order to reach the mandatory age. The kids that have birthdays right after the cutoff can be up to 364 days older than kids that have birthdays right before the next cutoff, but are competing in the same age class. And guess what? Waiting that whole year during your adolescent years can give you HUGE advantages in terms of size and strength. This difference means you have more potential to get more practice and playing time, can develop better skills, have a better chance for the coach to play you even more since you are a better player, and can ultimately move on to bigger and better things....success breeds success. Malcolm examines hockey, soccer, basketball and a variety of sports and comes to the same conclusion that the successful athletes were typically born right after age-cutoff dates in their respective sport. In one study, 72% of kids on a Czech Junior World Soccer Team were born in January, February, or March ...where the cutoff date was, you guessed it, 1 January!
I applied this same understanding to the top-two ranks in sumo wrestling and "discovered" that ~66% (66% for Yokozuna and 67% for Ozeki) of the 111 Japanese wrestlers that attained these ranks dating back to 1855 were born in the 6 months between November 1 and April 30....meaning only 33% were born between May 1 and October 31. And only 8% of these 111 wrestlers were born between June 1 and July 31 during this dead period. Why is this since, statistically, 50% of the birthdays should fall in each of these two 6-month periods? What makes the time period from November 1 to April 30 a golden period to be born and increase your chances at making the top of the sumo period 33% higher than someone born during the other 6 months? Well, I unfortunately have to leave you at a cliffhanger, because the answer is, "I don't know". But have no fear, I will keep at this and provide you my best theory. Unfortunately, there has been no research in this area, at least none published in English that I could find. I tried correlating school cutoffs (The Japanese school year starts in April), but couldn't come up with anything reasonable. I tried looking at when they passed their sumo entrance physicals compared to their age, but couldn't come up with anything obvious. More research to follow, but I would love to hear your thoughts and if you have any theories.
But, based on this research, I predict the next Ozeki (and maybe Yokozuna) will be Mitakeumi, born right in the middle of this 6-month golden period, 25 December 1992!!!
My friend's son plays competitive hockey and said there was definitely an advantage to being born in certain months. Can't remember what the formula was, but it has to do with start dates and size advantage.
ReplyDeleteDefinitely! That formula is the key to the competitive advantage.
DeleteI have read that book - eye opening. Well, up to March is the cutoff date for the previous school year. Anybody born in April would have the best chance to be larger and stronger than his peers, and they would be younger for every month after that with the youngest (higher chance of being smaller, weaker) being born in March. How this might apply later down the road is up for debate.
ReplyDeleteThere is a small spike at the beginning of April which can be attributed to this, but there are noticeably more from November up through mid April than the rest of the year. Which is even opposite of the higher birth months in the summer time and early fall. I added the chart to this post to help visualize.
DeleteBut for sure a kid just out of JHS joining sumo born on April 1st has a higher chance of being bigger and stronger than all the out of JHS boys who joined in the same time as him. Works for after high school too. Again, it is hard to see how this would help much down the line. Certainly might mean you were less likely to drop out if bigger and stronger? hmm..
ReplyDeleteI didn't run the exact numbers, but it seems like a good amount of the Japanese Yokozuna and Ozeki joined right after junior high. I think there is only one college graduate that ever made Yokozuna. So if this was a competitive advantage, it would only help up through Junior High. But again, the spikes should all start on April and run through the summer and dwindle out in the winter and spring up to 1 April if age cutoff was in play here. I don't believe it is...seems like something else is going on.
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