EURO 2016: Composition of National Teams

The UEFA EURO 2016 kicked off last week with 24 national football teams competing during the next month for the title of continental champion of Europe. One question on the minds of fans, managers, and industry is how much team composition rules have influenced the performance of certain teams.

• Seventy-two percent of the players on the Spanish national team—winner of the two most recent championships, EURO 2012 and 2008—play for Spanish football clubs. 
  
• In fact, 11 out of 16 finalist teams from the last eight UEFA Euro championships have a current roster composed of a majority of players who play exclusively for domestic clubs.

A player was historically permitted to represent any national team as long as he was a citizen of that country. In 2000, FIFA made national team eligibility rules more stringent to require a player demonstrate a "clear connection" to the team he wants to represent. A player meets the standard if he has been a resident for at least two years in the team country or has at least one parent or grandparent who was born in that country.

Outside international competitions, each sportsman may continue to play under contract for any football club of choice unless otherwise restricted by the national team. Since clubs do not have a clear connection requirement, athletes may play in parallel for a country's national team and for another country's club. National team thresholds governing how many of their players may represent other countries' clubs, however, has de facto acted as a clear connection requirement. 

• All members of the English national team play for English clubs.
• In contrast, no member of Northern Ireland's national team plays for domestic clubs, members generally preferring English clubs. Similarly, only one member of Albania's national team plays for an Albanian club, while the rest of the team plays for clubs of 13 different countries. 

Does team composition directly influence national team performance in international competitions like the EURO 2016? Ultimately, national team composition shifts continuously, changing not only national club representation among the team but the skills, experience, and internal dynamics of the teams, requiring a more detailed analysis of team performance to understand the influence of FIFA’s “clear connection” requirement.