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INTERNATIONAL JOURNAL OF SPECIAL EDUCATION Vol.37, No.3s, 2022
SPECIAL ISSUE ON WORLD OF EDUCATION AND REHABILITATION
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Systematic Review: Mechanism of Relative Age Effect in Sport
Nur Raifana Shazana Jasni1, Tengku Fadilah Tengku Kamalden1∗, Jorrye Jakiwa2, and
Mohd Rozilee Wazir Norjali Wazir1
1Department of Sport Studies, Universiti of Putra Malaysia (UPM), Malaysia
2Defence Fitness Academy, National Defence University of Malaysia (UPNM), Malaysia
The importance of talent identification (TID) in sports development could not be denied
where it could be a change on career pathway for an athlete, and this is also might cause
the talent loss when scouting the team and this are very crucial at grassroots to elite youth
level. The relative age effect (RAE) has been studied widely in sports where there is an
advantages and disadvantages occurred and lead to the talent loss. Many of the sports
does not have a standardized TID process which most of them are based on try and error
and expose to biases. Literature on this paper was obtained from computer based sources.
This research paper will discuss and elaborate more on the mechanism that might be
affecting the present of RAE which are maturity, playing position, gender and
performance and its possible solution which is important for the future development to
help researchers, sports & health professional, coaches and athletes understand the
concept of RAE and the solution selected.
Keywords:
Relative age effect; maturity; performance; sport development; birthdate
I.INTRODUCTION (TALENT IDENTIFICATION)
In sports, there are essential areas within sports development and one of the main areas is
talent identification. Talent identification is considered as crucial part in ensuring the higher
potential of an athlete can be achieve with the right sport and synonym with grassroot level.
The word talent means a special or an innate ability to achieve a success (Larkin and Reeves,
2018). While talent identification is known as a process to identify a future successful athlete
within the time of observation by making a prediction (Larkin and Reeves, 2018). Talent
identification aims is to identify, capture, choose and promote the athlete who has the most
potential, skills and capabilities to increase the chances for success and achievement in the
future and to be developed to be a top player (Pruna, Miñarro Tribaldos and Bahdur, 2018).
In football, the process of TID involves measuring the player physical and physiological to
find out the potential success outcome (Pruna, Miñarro Tribaldos and Bahdur, 2018). By
measuring those factor from time to time may predict the athletes performance and this
performance characteristic are based on the required skills used during the games (Pruna,
Miñarro Tribaldos and Bahdur, 2018).
Many of the sports does not have a standardized TID process which most of them are based
on try and error and expose to biases. Most of the sports academy are using certain cut-off
date to identify a group of talent based on their chronological age. One of the biases that may
occur during this process is the sports specific physical needs which lead to give effect on
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relative age. This effect known as relative age affect where selected athlete is likely
overrepresented in older athlete who tend to be more developed in terms of physical and
physiological who give advantages during the selection (K. Suppiah et al., 2020) and cause
uneven sports development for those who born later with the same year. In the following, this
paper will discuss on the mechanism of RAE in sports which are maturity status, playing
position, gender and performance.
II.MATERIAL AND METHOD
Literature on the relative age effect in sport focusing on grassroots to elite level was obtained
from several computer based sources. Relevent articles were located by using google scholar,
ResearchGate and ScienceDirect. The following keywords were used: “relative age effect”,
“birthdate”, “performance”, and “maturity”. All articles are from original English version
containing relevant data on relative age effect in sport.
III.RELATIVE AGE EFFECT (RAE)
Relative age effect (RAE) is known as a situation which there is the different in terms of
performance where children born early in the same year tend to be more perform than
children born later for the same cohort (Aune et al., 2018). These situation or phenomenon
has been widely studied and proved since 1980’s. The present of RAE can be found in
basketball (Safranyos et al., 2020), football (K. Suppiah et al., 2020), handball (Saavedra and
Saavedra, 2020), athletics (Brustio et al., 2019) and other sports both in female and male
category. This section will discuss on the existence of relative age effect (RAE) in sports and
the mechanism of (RAE).
A. The existence of RAE in sports
The displayed of better performance for older children and adolescent which usually come
with heavier and taller than the elder seem to be the RAE to occur (Barrenetxea-Garcia et al.,
2019). Moreover, according to (Tribolet et al., 2019), in the study for U10 to international
level, RAEs appears between age 10-12 to senior professional competition. However, the
existence and the intensity of RAE bias are vary depending on the countries, clubs, and a
different level of talent (Doyle and Bottomley, 2019) and agreed to be more observed in
grassroot to elite youth level.
B. Mechanism in RAE
1. Maturity Status
The progress towards adult state is referring to biological maturity (Hill et al., 2019) and the
state of biological maturity at the time it is observed known as maturity status (early, average
and late maturing) while maturity timing is refer to the specific maturational event occur
(ages at peak height velocity) (Myburgh, Cumming and Malina, 2019). In most sports,
athletes are grouped according to their chronological age which however might consist of
difference biological maturity (Cumming et al., 2017).
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According to (Müller et al., 2018), biological maturity proved to have a strong relationship
with the RAE where this might lead to the talent lost. This is exactly what was reported in
(Brazo-Sayavera et al., 2018) where the authors mentioned that maturity status and sport
organization can give negative impact to the chances for late developers to success from a
long-term sport performance. This finding is supported by (Cripps et al., 2017) players
identified onto the AFL TP at the U16 level are likely to be more biologically mature
(typically advance in height and heavier) than their non-talent identified counterpart. The
‘maturation-selection’ hypothesis as a mechanism for RAEs was highly supported (Brazo-
Sayavera et al., 2018). To identify the maturity status in sports, the used of non-invasive
method are popular, safe and cheaper than the invasive method.
Few studies have been using the non-invasive method to identify the maturity status in their
studies in sports. (Khamis and Roche, 1994) non-invasive method is popular among
researchers who do studies in maturity. (Myburgh, Cumming and Malina, 2019)
demonstrated that the use of percentage of predicted adult height (PAH) at the time of
observation based on skeletal age (SA) in comparison with predicted age at peak height
velocity (PHV) is correlated better. Both methods were classified as late, average or early
maturing. Spearman’s rank order correlations and kappa coefficients was used for the
consistency of the classification. The results showed that all data in both sexes using
percentage of predicted mature height, are moderate while the results are varied based on
predicted age at PHV where there is positive and low in girls and negative and moderate in
boys.
The percentage of predicted adult height has also been used as a measure the effect of
biological maturity status and relative age upon self-regulation in male academy soccer
player Cumming (biological maturation). This method required player to measure their
height, weight, age and their parent’s height (measured by staff or self-reported) to get the
mid-parents height and the maturity status are defined based on the PAH where players with
closer height with predicted adult height are more advance.
Another Peak Height Velocity (PHV) equation proposed by Mirwald (Mirwald et al., 2002)
has been used widely. Muller (Müller et al., 2018) assessed the age at PHV as suggested by
to calculate the maturity influences the relative age effect for the total of 222 male
participants of the under-9 Euro championship Soccer Tournament 2016 held in. Standing
height and sitting height, were taken from participants to identify the leg length. Based on the
data, date of birth, actual chronological age on the testing date and body weight were used to
calculate the predicted APHV. Players are then divided into three group of maturity level
(early, normal and late) where most of the players was identified as normal maturing
(168.5%), early (16.2%) and late (15.3%). No significant different was found from
predictable normal distribution (p = 0.007). Further investigation has been done and the
findings shows that there is significant difference between the observed and expected normal
distribution. Q1 showed high percentage of late maturing (27%) and high percentage of early
maturing (31%) while small percentage late maturing present (8%) in Q4. This results stress
that the RAE is clearly present and the selection of the Under 9 player are strongly related
with the relative age and biological maturity status.
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To proof if the RAE and maturity occurrence in the sports participations selection, (Baxter-
Jones et al., 2020) study this phenomenon between selected and unselected in youth team
from several sports. The biological age was identified using the age at PHV equation and the
RAE was analyzed. It was found that there is a bias towards larger and mature participants
which determine to have early in age at PHV and this is likely to be seen in males’ sports.
These results are differed in female sports participants except for hockey team where there is
no maturity bias identified for both selected and unselected participants.
2. Position of players
In team sport such as football, there are several different playing positions that might be
differ accordingly to the match tactical and role which includes difference physical
characteristic need. Thus, this difference might influence the RAE based on the playing
position and lead researchers’ interest to study this occurrence. In the recent studies of U16
2018 AFC football tournament, overall birth distribution are higher with player born on the
first quarter and the birth distribution are even across the playing position (K. Suppiah et al.,
2020). It is however different with the study in handball. According to (Fonseca et al., 2019),
the RAE was present among U19 handball athletes with most of the athlete born on the first
two quarter. In terms of playing position, the birth distribution for goalkeepers and pivot
position are fair and differ with wings and backs position where mostly are born in the first
quarter (Fonseca et al., 2019).
3. Gender
The differences of RAE presentation in sport between male and female athletes has been
studied widely. Some of the findings showed that there is no RAE presentation for female
athletes. This is supported by the recent study which found that there is no RAE in female
participants medal winning group compared to male category in elite water polo players
(Barrenetxea-Garcia et al., 2019). Consistent with this finding, no RAE found in MSSM
swimming overall female athletes in all age groups (Marapen and Jeffrey Low Fook Lee,
2015). In addition, it was found that RAE does not have linked to shooting performance even
though the male performance is better than female (Mon-López et al., 2020). However,
several findings showed the existence of RAE in female athletes. For instance, (Costa et al.,
2013) found that the RAE presented for 12 years old swimmers and another studies in
Spanish track and field sport showed the high presentation of RAE in both gender at U18 and
U20 level (Brazo-Sayavera et al., 2018). This phenomenon might happen due to the limited
participants and competitiveness for female athlete compete in certain sport which lead to
difficulty to do deeper study on RAE among female athletes (Musch and Grondin, 2001;
Costa et al., 2013; Brazo-Sayavera et al., 2018).
This is different in males’ findings where most of the findings showed the RAE presentation.
In South Korean football analysis, RAE is highly represent for age U16, U17, U19, U20 and
U23 with more players born in the first quarter of the year compared to those in the last
quarter (Jeong et al., 2019). According to research by (K. Suppiah et al., 2020), the RAE was
demonstrated in the 2018 AFC U16 soccer tournaments with the large number of older player
in the qualified team. The RAE will less present in the senior team (Jeong et al., 2019). This
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finding supported by previous study in 2015, where there is presentation of RAE among
overall male swimming participants except for U18 age group (Marapen and Jeffrey Low
Fook Lee, 2015).
4. Performance
To extend more knowledge on the impact of uneven birth distribution towards performance
either individual or team sport, an analysis has been done by several researchers. For example,
in the recent study of handball game for World Men’s Handball Championship 2017, based
on the final ranking, overrepresentation of athletes born in early month of the year in the
quarter-finalists, octaves-finalist and bottom eight while for semi-finalist was evenly
distributed (Fonseca et al>, 2019). Another study in rugby sport, stated that the recipient for
AFLs best award and fairest award are more likely born in the first half of the year (Tribolet
et al., 2019). However, the results may vary depending on type of sports and age. To support
this statement, it is found that in shooting sport, RAE are unlikely to have any impact on the
shooting performance (Mon-López et al., 2020). Further finding to understand the correlation
between RAE and performance can be found in (Marapen and Jeffrey Low Fook Lee, 2015)
where among swimming MSSM medal winners between male and female participants
showed that there is no linkage in between medal winners and RAE.
IV.RESULTS & DISCUSSION
The purpose of this paper is to discuss the mechanism of the relative age effect in sports and
mainly focused on grassroots to elite youth level. This discussion may be useful for
researchers or sports practitioner to understand the mechanism of RAE and identify which
mechanism of RAE affected their sports club setting the most to provide better solution of it.
The maturity status has proven to give impact on the selection biases. Thus, few researchers
has started to identify the used of biological age in the selection and grouping according to
the anthropometric measures which this idea was named as bio-banding (Baxter-Jones et al.,
2020). This can give solution to the maturity differences in sports (Webdale et al., 2019).
Two different method has been suggested to be used to identify the maturity status is by using
(Khamis and Roche, 1994) predicted adult height and (Mirwald et al., 2002) peak height
velocity.
Playing position is one of the RAE mechanism and this mechanism are generally for team
sports such as football, rugby, netball, and hockey. The differences of RAE presentation
according to the playing position is probable due to the position specific requirements which
is needed to perform specific skills during athlete’s selection. For instance, back position in
handball are to perform defense movement which need athletes with more bigger and higher
strength level (Fonseca et al., 2019). In general, early born athletes tend to be more
biologically mature and have advantage for a greater strength, height, speed at the time of
observation (Fonseca et al., 2019; Tribolet et al., 2019). The used of age-ordered shirt
numbering might be used to reduce the relative age effect sports team where no athlete’s
information were given to the talent scout team including the playing shirt correspond to the
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relative age (Mann and van Ginneken, 2017). However, since this method only has been
tested once, more research is needed to ensure the reliability.
Athlete who have undergo long term development training where technically will increase
their technical skill will overcome the player with physical advantage (Marapen and Jeffrey
Low Fook Lee, 2015). The absent of RAE in female participant and successful athletes are
likely due to the popularity of the sports itself which may be known as male sports and the
level of participant’s skills across the development process respectively (Marapen and Jeffrey
Low Fook Lee, 2015). Thus, the sample size for female participants might influence the
evaluation.
One of the solution as suggested by (Romann and Cobley, 2015) to reduce or eliminate the
present of RAE, is a corrective adjustment after performance method that has been used in
athletic sprinting and was successfully eliminate the RAEs. The used of corrective adjustment
can be seen in golf where the handicap is being used to identify the athlete performance level
(Romann and Cobley, 2015). In any proposed solution, it may have the strength and
weaknesses. This method is easy to apply in any other sports but may be limited to individual
sports. In addition, it is difficult to control the inter-individual variability which the relatively
young athlete might have similar physical and skills with the relatively older athlete (Romann
and Cobley, 2015). To support this finding, (Stephen Cobley et al., 2019) has tested this
method in swimming. The results showed that the RAE has successfully removed with the
used of corrective adjustment method in 100m Freestyle swimming and this might reduce the
effect of performance on RAE.
Some researchers proposed limit the player quota according to the quartile which is more
sensitive to the physical characteristic individual variability (Barnsley, R. H., & Thompson,
1988; Helsen, Starkes and Van Winckel, 2000), delay selection to 15 or 16 years old to
eliminate the early specialization and give experiencing to all youth ages (Cobley et al.,
2009). However, further research needs to be done to identify the effect to player
development especially that relatively older player has advantages generally in physical
characteristic.
Another proposed solution is by dividing the age group according to the age band or different
cut-off date. Generally, in sports development program, the used of 12-month bands has been
widely used especially in Malaysia. In this propose solution, the author suggest changing the
age band into 9-, 15- or 21-month bands (Boucher and Halliwell, 1991; Brewer et al., 1995;
Musch and Grondin, 2001) to reduce the gap of age difference. However, this solution might
just shift the RAE into different group and are not suitable for sport league where the
teammates are always be changed (Webdale et al., 2019). This encourage other scholars to
identify solution for RAE according to the specific sport need.
V.CONCLUSION
In summary, there are a few mechanisms of relative age effect and possible solution can be
used has been discussed in this paper. Furthermore, the results of this RAE are vary
depending on the sample size, playing position and athlete sporting level. For example, small
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sample size in female participation might hide the RAE appearance. Although there are many
proposed solutions suggested to be used during selection and after performance, but it is
important for sports organization to identify what is the mechanism of RAE occur in their
own club so that the solution can be specifically addressed and therefore can improve the
talent development program.
VI.ACKNOWLEDGEMENT
This research work is supported by Universiti Putra Malaysia (UPM) under the Department
of Sport Studies, Faculty of Educational Studies. This research also completed with the help
of my supervisor committee Dr. Tengku Fadhilah Tengku Kamalden, Dr. Jorrye Jakiwa and
Dr. Mohd Rozilee Wazir Mohd Norjali Wazir. Their supervision, knowledge and enthusiasm
keep me on track from the beginning.
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