Academic research that explains who makes the team

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Research paper that explains the Relative Age Effect in soccer, a documented bias that favors older kids within each age group.

http://www.dkysa.org/RelativeAgeEffe...nEtAl_2005.pdf

[Unregistered]

Research paper that explains the Relative Age Effect in soccer, a documented bias that favors older kids within each age group.

http://www.dkysa.org/RelativeAgeEffe...nEtAl_2005.pdf

It has an effect on professional sports too:

The distribution of professional soccer players' birthdays in the Australian, Brazilian (n=486), German (n=355), and Japanese (n=360) leagues (1995/6 season) were compared by month. These birthday distributions were then compared with that of the general population. It was hypothesized that skewed birth rate distributions among sports professionals can be interpreted as evidence of a systematic discrimination against children born shortly before the cut off date for each age grouping. A strong relative age effect in professional soccer was found in Germany, Japan, Brazil and Australia, showing that the effect is independent of different cut-off dates and variety of climatic and sociocultural factors. A shifted peak in the birth date distribution of Australian soccer professionals paralleling a corresponding change in the cut-off date in Australian soccer in 1989 was also established. This pattern of results provides strong evidence for the cut-off date in youth soccer as the main cause for the relative age effect in professional soccer.

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It has an effect on professional sports too:

The distribution of professional soccer players' birthdays in the Australian, Brazilian (n=486), German (n=355), and Japanese (n=360) leagues (1995/6 season) were compared by month. These birthday distributions were then compared with that of the general population. It was hypothesized that skewed birth rate distributions among sports professionals can be interpreted as evidence of a systematic discrimination against children born shortly before the cut off date for each age grouping. A strong relative age effect in professional soccer was found in Germany, Japan, Brazil and Australia, showing that the effect is independent of different cut-off dates and variety of climatic and sociocultural factors. A shifted peak in the birth date distribution of Australian soccer professionals paralleling a corresponding change in the cut-off date in Australian soccer in 1989 was also established. This pattern of results provides strong evidence for the cut-off date in youth soccer as the main cause for the relative age effect in professional soccer.

The unanswered question is "is there an actual physical performance correlation?"

It will take an age and identity blind evaluation process of players at the college and professional levels to determine if there is an actual physical reason or are the earlier established reputations of the players carrying over. It would also be interesting to see the strength of the age correlation by sex. Since girls mature sooner the correlation should be weaker as the girls have more years with equal physical abilities prior to college. However my experience with ODP girls would say that those that mature early get locked in regardless of their comparative skill @ U17-20.

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The unanswered question is "is there an actual physical performance correlation?"

It will take an age and identity blind evaluation process of players at the college and professional levels to determine if there is an actual physical reason or are the earlier established reputations of the players carrying over. It would also be interesting to see the strength of the age correlation by sex. Since girls mature sooner the correlation should be weaker as the girls have more years with equal physical abilities prior to college. However my experience with ODP girls would say that those that mature early get locked in regardless of their comparative skill @ U17-20.

From my reading of it, the effect is more pronounced with boys due to the earlier maturation of girls, as you say.

Yes, it's not just a physical difference, but also emotional maturity and the additional playing time (experience).

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Except

From my reading of it, the effect is more pronounced with boys due to the earlier maturation of girls, as you say.

Yes, it's not just a physical difference, but also emotional maturity and the additional playing time (experience).

That does not explain the phenomenon in the later years, especially the pros, where they players have had the same size and the same length of training!

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the effect is cumulative / compounding

the effects stack up, year after year. more playing time. better coaches. better competition. increasing expectations. in fact, I've noticed that for my son's generation, the opportunity to specialize in one sport all year round starts at a much earlier age. In 10 years, the effect may be even more pronounced.

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That does not explain the phenomenon in the later years, especially the pros, where they players have had the same size and the same length of training!

IIRC, one explanation given is that, at the younger ages, the older kids within the age group are nurtured more and the younger ones get discouraged and fall away from the sport.

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the effects stack up, year after year. more playing time. better coaches. better competition. increasing expectations. in fact, I've noticed that for my son's generation, the opportunity to specialize in one sport all year round starts at a much earlier age. In 10 years, the effect may be even more pronounced.

So you are saying once 6 months behind always behind......whawh awhahwhahwhah. If that was true all the pros would be 30 years old where the skill peak meets the physical peak. No there is something else going on.

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I've seen that!

IIRC, one explanation given is that, at the younger ages, the older kids within the age group are nurtured more and the younger ones get discouraged and fall away from the sport.

If the younger players are also smaller and not as fast and or quick I have seen this phenomenon, however this still does not explain the results at the professional level where they HAVE stuck with the sport and have received the same level of coaching and training opportunity.

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SuperFreakonmics touches on this phenomenon as well. Their take on it was that many of the players get discouraged and drop out. Even so, they point out that this is a trait that only seems to apply to the median player rather than the exceptional players where the percentage did not hold up. It makes sense that if young players are not given playing time and do not feel successful that they will not continue with the sport. This age bias is seen in all sports. Another interesting correlation is that among families who have excelled at a particular sport (say baseball) and the entire family is involved in the sport that there is no correlation between birthdate (age) and success. Again, this speaks to the amount of nurturing given to those individuals whose families love a specific sport.

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"Again, this speaks to the amount of nurturing given to those individuals whose families love a specific sport."

So the younger kids without nurturing drop out which is too bad. I am not sure what the fix is for this. I find it encouraging that ODP uses a different cutoff date - maybe that helps even things out a little?

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"Again, this speaks to the amount of nurturing given to those individuals whose families love a specific sport."

So the younger kids without nurturing drop out which is too bad. I am not sure what the fix is for this. I find it encouraging that ODP uses a different cutoff date - maybe that helps even things out a little?

You may have hit on something. See
http://lastplanetranking.***********...ew-effect.html

There is an overweighting of Jan and Feb kids on Development teams (like ODP) which use a calendar year.

[Unregistered]

Outliers

This topic is in the book "Outliers" as well a few other notable phenomena such as the "10,000 hours" effect.