The birth-date bias: why football’s greatest talent may never get spotted

Most elite youth footballers are born at the start of the selection year, giving them a physical edge. Those born just months later are often smaller, weaker—and ignored by scouts. Professor Tim Coulson missed out on football glory for that very reason. Now science may offer a fairer way to find the next Messi

If I had been born a month and a day later, you’d have frequently seen my photo in the sports pages of newspapers. In pubs and bars across the land, football fans would have been discussing whether Pele, Maradona, Messi or Coulson was the greatest of all time. But it was not to be. I was born in the wrong month, at the tail end of the footballing year. That meant I was tiny compared to many of my classmates, and my nickname was ‘Tot’ from tiny tot. I never made the school teams, and I ended up better at table football than on the soccer pitch.

A staggering 55% of elite junior footballers are born in the first quarter of the footballing year, with less than 8% having birthdays in the last quarter. Being older than the rest of their cohort, they tend to be better developed, more coordinated and perceived as being more talented. These older kids start school, and their sporting career, with an advantage: they not only get the benefits of being selected younger, but then get more specialised training at elite academies. It is not just football where this bias is seen. It is prevalent in many sports where teams compete against one another, including American football, baseball and ice hockey. People born later in the year have to be much better than older members of their cohort to make it in these sports. The December-born Brazilian player Raphinha who now plays his club football with Barcelona is a case in point. The ¢84M (£75M) footballer was young and small for his year. He trialled at various Brazilian teams but played all his youth football on the streets of Port Alegre where he was missed by scouts. He was spotted in a street game where he was playing at the age of 18. His story makes you wonder how many hundreds of talented players worth billions of euros are out there who could help win the premiership but are instead working off the playing field.

Talking to the Science of the Times podcast that I co-host, Professor Robbie Wilson of the University of Queensland said: “Young members of cohorts are disadvantaged right at the start of their sporting journey, with most being doomed to careers off the sports field. In parts of the developing world football is one route out of poverty, and this is even less of an opportunity for individuals born in the wrong time of year”.

In his research, Wilson discovered and quantified significant differences between individual animals, like crayfish, in their ability to move stealthily, capture prey, and solve tasks. Some were naturally talented at some tasks, but hopeless at others. Yet practice could often improve performance. Wilson says he and his colleagues have shown that with the right training “individual animals of some species become better at some physical challenges”.  A colleague of Wilson’s at the University of New Orleans, Professor Simon Lailvaux, produced ‘racing lizards’ by training them to run quickly for a reward. Over time they significantly increased their top running speed.  Wilson started to wonder whether football scouts and coaches could benefit from the methods used to study wild animals, and he now brings a new quantitative approach to spotting football talent where he works with several professional clubs, particularly in Brazil, a country with a huge pool of undiscovered footballing talent.

Wilson’s approach is straightforward, clever, and novel. He can mesh and interrogate data from multiple sources using analytical approaches he has developed. Data are collected from real matches where dribbling, passing and shooting performance are monitored, with information from small games such as rondos where one player tries to take the ball off three players who pass it amongst themselves, with insights from skills-focused tasks. He has designed these tasks to assess specific aspects of an individual’s footballing ability that he has shown are critical in real matches. The tasks involve the footballer rebounding a football off one kickboard when light appears, controlling the rebound with a single touch, before targeting another kickboard as it lights up. Different challenges involve using the back foot or front foot and moving in particular ways. The aim is to hit the largest number of kickboards using the right combination of controlling and kicking feet within a time limit. By modifying the number and position of kickboards, and the number of different colours that each kickboard displays, Professor Wilson has designed a slew of tests designed to separate out each footballer’s skills that accurately predict performance in competitive matches.

Professor Wilson said: “My approach is scientifically supported with large amounts of data from footballers in Africa, South America, Europe and Australia”.

He went on to tell the podcast: “I can not only spot promising talent, I can also design kickboard challenges and small games to help them improve their game”.

The Australian sports science expert also explained how his technique can be used to rapidly assess thousands of wannabe footballers, quickly weeding out those who just do not have the natural talent to go on to succeed at the highest level. Traditional coaches can then focus on a few tens of players deciding which ones to offer a club deal.  Professor Wilson explained that “if you couple my approaches with rules that require teams to field players born in each quarter of the footballing year, I could increase access to football as a career while spotting new talent”.

If Wilson’s approaches had been available, and such rules had been in place when I was growing up, perhaps you would be reading about Steamy Spice and Coulson on the back pages of the newspapers rather than Posh and Becks. Though as the video of the podcast hosts being put through their paces by Wilson clearly shows, I probably would have never had any natural footballing talent in any alternative universe.

Professor Tim Coulson is a biologist at the University of Oxford, where he has led both the Zoology and Biology departments. He previously was Professor of Population Biology at Imperial College London and held positions at Cambridge University and the Institute of Zoology London. A highly decorated scientist with awards from major institutions including the Royal Society, he has edited leading journals and served on Government advisory boards. His first book for general readers, “A little History of Everything: from the Big Bang to you” (Penguin Michael Joseph), traces the 13.8-billion-year story from the Big Bang to human consciousness and is available to buy on Amazon. He is co-host of the Science of the Times Podcast with Professor Syma Khalid.

Main photo: Kampus Production/Pexels