What is it?
The relative age effect (RAE) refers to a preference for selecting footballers born earlier in the year, often due to enhanced maturational factors (sometimes being bigger, faster, stronger physically but that is not universally supported by research, can also be more cognitively and emotionally mature) over their teammates born later in the year. As the graph above demonstrates, there is potentially the difference of a year growth between youth players!
Why is it a problem?
This can lead to a biased view of ‘potential’, which leads to these players being exposed to more game-time, getting selected for representational squads, receiving higher standards of coaching and leading to greater training opportunities. It’s often these factors that make players (especially in their early teens) stand out, stamina means it’s the fittest player still being seen to make challenges late on in games, a tall player will often stand out from the rest. It’s the same reason that there was an issue with one particular scout from a big English club always coming back recommending blond players… scanning a field of players, the blond heads tended to stand out!
The impact of this is that younger, talented players can often be overlooked. How many times have you seen a coach ‘picking all the big fellas to head to the Kennedy cup’ or chatted about whether Messi would’ve come through the Irish system?
Where is it an issue?
Almost everywhere! It’s been found in many countries, different levels, age bands. Interestingly, it’s more prevalent in what would typically regarded as ‘stronger’ leagues and particularly in bigger cities. The theory being that the greater the pool of players, the more coaches can select the bigger players at the expense of smaller players as there’s more of them to choose!
Is it an issue here in Ireland?
I analysed the birth rates of all players on 6 years of the FAIs national Emerging Talent Programme (original structure). I compared this to the birth rates of the general population of boys from the same years (from the CSO). For ease of analysis, the 12 months were combined into 4 quarters of the year (quarter 1= January, February, March, quarter 2 = April, May, June, quarter 3 = July, August, September, quarter 4 = October, November, December.
For the general birth rates each quarter showed remarkably similar distribution of birth rates…. Roughly 25% born in each quarter.
So you might assume is that the ETP sample should be the same right?
Why would it be different? Surely it should follow the same patterns as the general population of boys that age. It’s worth noting here that unlike many other national FA’s, the FAI don’t have a central data base of all of their players throughout the country that of course would’ve been the ideal comparison!
What you can see in the graph above is that actually the ETP sample isn’t as evenly spread as the national sample. Instead of a consistent 25 (ish!) percent born in each quarter, it varies from 38.2 from quarter 1 to 12.6% being born in quarter 4. So players born in January, February and March are over represented whilst the poor winter babies of October, November and December are underrepresented. We can break this down into the actual months for a closer look (in most studies February dips a little, usually attributed to the shorter month), it shows that there’s over 4.5 times more players selected that are born in January versus December.
You’ll remember that earlier I mentioned about the RAE being more prevalent in stronger leagues and bigger cities… let’s have a look at the DDSL only (‘Dublin District School-boy League’, one of the largest schoolboy leagues in Europe). Its figures eclipse the national RAE findings, with the quarter one births (blue columns below) now shooting up to 43.8%, almost half of the ETP sample that came from the DDSL were born in the first 3 months of the year. There are 4 times more players born between Jan-March than between Oct-Dec in the ETP from this league (and as you can see from the CSO stats, it’s not as if the general population is just born that way).
For research purposes nosiness on my part, I broke the most commonly represented clubs on the ETP down individually. The clubs with the most quarter one births were Cherry Orchard (51.6%), St. Kevins (43.8%), Belvedere (44%) and Malahide Utd (43.5%).
If in the case of these clubs, over half of their players were born in quarter 1 that means that there’s very little space on squads for players from the other 9 months of the year! Are the players that are migrating into the league the older/ more physically mature players from elsewhere? Does the numbers they can draw from mean that they can keep selecting larger players? (Anecdotally, anyone that’s been down at the Kennedy cup has probably seen the visual differences between the DDSL squad and other teams).
If you’re involved with a school boy league around the country you can check below how your league fared on the breakdown of quarters of birth (according to the statistics Limerick District and Longford have the most even spread of births across all 4 quarters). The ‘total’ column relates to how many boys were on the programme and the overall percentage (e.g. the 37 boys from Athlone league accounted for 2.17% of the total cohort on the ETP), then you can read the breakdown of quarter births (e.g. staying with Athlone, 16 boys were from Q1, which was 43.2% of all their boys involved).
The coaching ‘so-what’:
Coaches are an important agent for changing the effects of relative age within Irish youth sport. Challenge your perceptions, challenge what exactly is it that makes this player stand out? When everything levels out in later teen years will he/she still have enough to set them apart?
Physically more mature players (remember though that maturity and RAE are two separate concepts!) are more likely to be identified as ‘talented’, thus get selected for advanced coaching and training and compete at higher levels of competition such as ETP. Success in youth sport can lead to an increased sense of motivation for these players due to the positive and reinforcing nature of feedback obtained from coaches, parents and peers and this can lead to greater effort and better performance by the athlete. Conversely, de-motivation, resulting from a lack of selection, or the perception of a selection bias, could lead to increased levels of drop out among the remaining players. This in turn could perpetuate the increased levels of players represented in the first two quarters (I’ll come back in a later blog about why the RAE is reversed at a professional level!).
What can be done?
Rotate cut-off dates for younger age groups, provide additional support for younger players through development stages, for the larger clubs have Jan – June and July to Dec squads. A key factor is to limit competition at younger age-groups, this can help to put the focus on longer term development rather than on short term ‘winning’. Coach education (and resourcing!) is key to addressing this inequity.
Interested to read more?
This was an excerpt from a journal article published earlier this year in ‘Science and Medicine in Football’ by Laura Finnegan. If you’re sitting there thinking about the tall, blond centre back you’ve been raving about all year and you want to know more, you can read the full thing and source the references cited by following the link below: