Bio-banding in football; fad or fallacy?

A Scottish newspaper ran an article recently on the use of bio-banding to organise youth tournaments (you can read the article here if you are interested (http://goo.gl/4lncmF)) which was followed up more recently with a post on BBC sport.  For those of you unfamiliar with bio-banding it is a method of categorising young players based on their biological rather than chronological age.  The suggested benefit being that players get to compete with peers who are of a similar stature and mass making it easier (?) to spot those with greater technical proficiency.  Given the financial incentives of nurturing talented young players within a club’s academy system the notion of being able to steal a march on the competition is appealing however is bio-banding the way forward?

Before I address the philosophical issues there are some important methodological considerations which warrant a mention.  Firstly, assuming each child has a legitimate birth certificate chronological age is easily determined with a high degree of accuracy.  Biological age on the other hand poses more of a challenge.  The most valid method is to x-ray the wrist to determine skeletal age; some ethical questions exist around this method, not to mention the associated expense making it inaccessible to most.  A number of surrogate markers have been proposed, the most popular being an equation that uses mass, stature and seated stature to predict the maturity offset and years from peak height velocity (PHV).  Interested readers can view the original paper here (https://goo.gl/CI0AsO).  Whilst measures of stature and mass are accessible to most people it does require a level of accuracy in how the measurements are taken.  Furthermore, the accuracy of the equation improves with the more individual data points you collect bringing its use into question when used singularly before a tournament.  Finally, in every measure there is usually a degree of inherent error and maturity offset is no exception.  Wherever you set your cut off points (and this is as essential when dividing players by biological as it is chronological age) the error in the measure means that some will still be categorized incorrectly.

Putting these methodological questions to one side there are philosophical issues which are worth addressing.  The tournament reported by the Scottish Sun, to my knowledge, was for players already attached to academy teams which prompts the question, is bio-banding a talent identification or talent development tool?  For players who have already been identified by a club (and signed) I would expect coaches to track measures such as maturity status longitudinally allowing them to factor this in when assessing rate of improvement (itself a very subjective construct).  For example, if a club felt a specific player was too small we might expect then to cross check maturity status before making any decisions regarding their future.  Furthermore, I would suggest that for players who are either larger or smaller than their peers a number of ways exist to manage their development so that size is not a limiting factor.  For example, a player who is large for their age may have conditions placed upon them during training to limit how they use their physicality; being constrained to interceptions rather than tackling to regain possession of the ball.  This could be used in conjunction with short spells playing with older players of a more comparable size.  For smaller players, once selected, playing and competing with larger and heavier peers may be of benefit in the long term if they have a coaching team willing to give them time to develop.  Whether organising training and matches according to bio-bands represents a more valid method than those identified above in managing talented young players is of course debatable and I would be interested to heat counter points.

Bio-banding for talent identification purposes may be of more benefit.  We know from recent studies that the relative age effect exists within football, characterized by an over-representation of chronologically older players.  Facilitating opportunities for players to compete against size matched opponents, irrespective of age, may combat this. It should be remembered however that although the relative age effect exists there is limited evidence to suggest that chronologically older players display superior physical qualities, for example speed, agility and aerobic fitness.  Whilst there may be benefits in bio-banding there are also logistical issues in gaining anthropometric information prior to trial games or large scale selection tournaments.

There is no easy answer to this issue and I hope this does not discourage the pursuit of a solution.  It does however, and this may not appeal to the more scientifically minded, suggest a reliance on experienced scouts able to see past the size and shape of young players and recognise their ability to play the game effectively.  Having spent some time with an incredibly knowledgeable scout I would proffer that in this instance there really is no substitute for experience and a well-trained ‘eye for a player’.