Exploring age bias in US-based MLS academies

The recent national team call-up of Miguel Ibarra rekindled my desire to dig into just where the American size bias comes from. Ibarra was one of what I suspect are dozens (hundreds? thousands?) of small players with top-level talent but who get ignored by the US soccer scouting and development system simply because they don’t fit the mold of big-fast-strong that seems so pervasive in the sport here. 

Early this year I did some exploratory research and writing to look at the question, “Does MLS have a bias against small players?” Based on that research, I concluded that yes, smaller players in the US have a more difficult time turning pro than their European counterparts. However, the problem persisted at a similar rate as in NCAA Division 1 teams. That left me wondering just where does the size bias start?

As a U14 coach, it was pretty obvious that it was prevalent even at that age. We have all seen the typical man-child players who finished puberty early and completely dominate games on their own. Unfortunately, most of us can recognize that type of player is generally just bigger-faster-stronger and that allows them to get away with mediocre technical and tactical ability while still having a huge impact on games. Not to say that all big-fast-strong players don't have technical and tactical ability - I had a U14 6'5" centerback who was one of the most technical and least physical on the team and played alongside two other centerbacks who were both about 5'4" and more physical than the tall CB.

A recent article explored how there’s a noticeable bias in Europe toward youth players born early in the year. I have been trying to find a way to explore the size-bias question at younger ages, but actual size data hasn’t been readily available. That article gave me an idea for a proxy so I decided birth month was a reasonable proxy if we’re willing to accept two things: 1. Players born early in the year are more likely to be more physically developed than those born later in the year and 2. Technical and tactical soccer ability and potential are normally distributed through the months. If you disagree with either of those assumptions, I’d love to hear your reasoning.

Do US-based MLS academies have a bias toward older players?

I looked at the birth months for every player in every U14, U16, and U18 US-based MLS academy. Here’s the bar chart:

It is pretty obvious that the answer is yes, MLS academies have a bias toward selecting older players. January and February are the birth months with the most academy players. November and December had the least. In fact, Those born in the first two months of the year were 2.4 times more likely to find a roster spot than those born in the last two months.

However, there’s another story told in this histogram. There’s a significant jump between July and August. In the part of youth soccer that isn’t USSDA, the age cutoffs aren’t simply based on calendar years. They are usually right there at the July/August split causing the older players in an age group to be born in August and the youngest in July. This spike in August could tell us a couple different stories. There are two that I think are more likely than others. The first is that the older players (August born) stand out more due to their physical traits in games where MLS academy coaches scout to recruit players. The second is that the older players are more likely to make rosters of non-USSDA “elite” club teams and get more playing time there resulting in them being more likely to develop soccer skills. It is impossible to know which is the larger contributor, but I suspect both are true to some extent.

Conclusions

It is apparent there is definitely an age bias in the youth ranks. MLS academies are guilty of it as evidenced by the increased likelihood for January and February birthdays. Non-USSDA clubs are guilty of it as evidenced by the spike in August birthdays and subsequent decline.

I plan to look more in-depth at which academies are particularly guilty of this bias and what trend differences there are between U14, U16, and U18. Who knows when I’ll make the time to do that.