How bio-banding aims to stop bigger children running the show

This week it was revealed that Premier League clubs are bringing fewer players through their academies to the first team than in any of Europe’s other major leagues. There are many reasons for this, but one begins at birth. A baby born at the start of the school year in the UK has a head start in life, sometimes literally. They will be older, bigger and more mature than many of their school year peers. That helps them academically and also, since most age-group cut-off dates follow the school year, in sport.

A fellow student on the Youth Module 2 course described on these pages related a recent under-13s match his team had played. The opposition looked unusually tall. When this was remarked upon the coach said proudly: “I only pick kids born in September and October.”

Pathetic as this is at grassroots level, it also applies in the professional game. Clubs start recruiting at eight and the older kids, being bigger and more mature, stand out. One north-west academy had an entire group born in September and October.

A few years ago some at the Football Association and Premier League began wondering whether this was misguided. A study discovered 57 per cent of boys aged nine-to-16 in Premier League academies were born in the first third of the school year, but only 14 per cent in the last third. In society as a whole births are evenly spread through the year.

One of the clubs most intrigued was Southampton. The birth dates of their academy players reflected the relative-age effect but, says Alek Gross, the club’s head of sport science: “When we looked at senior England squads and British-born Premier League players there was an even spread.” Saints realised the players making the grade did not reflect the birth-date profile of those in their academy system. “We were potentially recruiting players, and retaining them in the academy, based on physical presence,” said Gross.

One solution has been to use “bio-banding”, which involves using a formula, in part based on parental height, to determine how tall a player will be when fully grown. Players are then grouped together based on what percentage of that adult height they have achieved. Someone who will be small as an adult will still be playing against taller players, but the ratio will equal what they will encounter when fully grown, not skewed by opponents having growth spurts.

Bio-banding does not just help late maturers, who, said Gross, “typically develop better technical skills to compensate for their lack of physicality” – like Lionel Messi, who was very small as a child. It also helps early developers, who fail to develop those skills as they can get by on size – until adulthood, when others have caught up and their lack of technique hinders them. “This gives them the chance to be the underdog and develop technical skills against players who are physically bigger,” said Gross.

Earlier this season Southampton hosted a tournament with players grouped by bio-banding, involving teams from Norwich City, Stoke City and Reading. This is still being assessed by researchers from Bath University but among comments from players participating were: “I had more time on the ball and was less likely to be muscled off it;” and “Team cohesion felt better, no one player dominated”.

Gross stressed: “It’s an additional tool, not replacing traditional methods. It may only affect one, two, three players that might otherwise be released, but long-term that is enough to make it worthwhile.”

The methods should also enable clubs to help players manage growth spurts, which can affect co-ordination and provoke injury, and assess them better when scholarship decisions are made. By 18 most players will be fully grown, but a player who has only just got there will have more improvement potential than one fully grown at 16.

In some cases players may be encouraged to stay down in a lower age-group while they mature. This happened at Barnsley with John Stones. He disliked it at the time, but his technical ability now shows the success of the decision.

More bio-banding tournaments are being considered, including those with an international dimension, possibly involving Dutch clubs, as similar work is being done in the Netherlands. In the long term the FA would like to move the cut-off point to 1 January, bringing England in line with other Uefa nations, and, because schools would stay at 1 September, reducing the relative-age effect. Resistance from the FA Council, backed by grassroots leagues, has so far prevented this.