The Centre International d'Etude du Sport (CIES) in Switzerland found the average has fallen from 20.2% four years ago. They took 'homegrown' as a player who had spent at least three years in a club's academy between the ages of 15 and 21.
Surprisingly the Premier League is not the worst offender; that crown is taken by Serie A's less than self-confident 10%.
France's first division clubs have the highest ratio however with almost a quarter coming through the youth ranks. Spain is close by with the much-vaunted German top flight somewhat behind, closer to England.
Ligue 1 24.6%
La Liga 22.4%
Premier League 13.9%
Serie A 9.6%
In terms of clubs from the big five leagues developing their own players, three of the top four are from La Liga.
Athletic Bilbao's regional recruitment tradition unsurprisingly sees them in the lead, along with Lyon, often cited as the model organisation for a club with modest resources. Real Sociedad make it two Basque sides in the top three.
- Athletic Bilbao 15
- Olympique Lyonnais 15
- Real Sociedad 15
- Barcelona 13
- Manchester Utd 12
- Bordeaux 11
- Metz 10
- Montpellier 10
- Lens 9
- Nantes 9
- Schalke 9
Real Madrid have eight players who grew up at the Bernabeu, Bayern Munich six schooled in-house, Atletico Madrid five, Inter four, Chelsea & Milan three and Manchester City only one. Empoli was the highest-placed Italian club with seven, the same as Arsenal.
Ajax, outside the five big leagues but with a legendary youth system, have 15 own-grown players, but are topped by Argentina's River Plate, with 17.
When it comes to importing players from overseas, the Premier League came top in 2013-'14 with a percentage almost twice as big as France's.
Premier League 63%
Serie A 55%
La Liga 39%
Ligue 1 32%
So the overall picture, at least in England and Italy, is of clubs buying in more and more talent despite spending a fortune on youth systems to avoid the huge costs that entails.
The situation is really quite curious. For ambitious young players trying to make it at Europe's biggest clubs, the best chance of success paradoxically seems to be to get transferred to another one.
- Sean O'Conor