Just because the likes of Manchester United, Real Madrid and Bayern Munich are paying hundreds of millions of pounds for stars in their prime, it doesn't mean they forget about one of the cornerstones of any football club.
From Barcelona's fabled La Masia to Manchester United's historic youth academy, the biggest clubs in Europe always have one eye on bringing through homegrown stars of the future.
But which clubs in Europe's biggest leagues have been the most successful at doing that in recent years? Well, thanks to a new study from the CIES Football Observatory, we have the answer. And it makes impressive reading for La Liga fans.
The 2016 study breaks down the most prolific youth systems across the continent by counting up just how many players who started their careers at clubs across Europe are now plying their trade in Europe's top five divisions - the Premier League, La Liga, Serie A, Bundesliga and Ligue 1.
They have also broken down the results into 'In' and 'Out' categories denoting whether the player is still at the club he joined as a youngster. So, without further ado, here is how the top 10 breaks down...
= 8 | Rennes | Total - 22 players | 'In' - 4 | 'Out' 18
The French side are regularly heralded as having one of the best youth academies in the world and have produced the likes of Sylvain Wiltord and Yoann Gourcuff in the past.
Probably their biggest success story in recent years is exciting striker Ousmane Dembélé who was sold to Borussia Dortmund this summer for €15 million.
= 8 | Monaco | Total - 22 players | 'In' - 5 | 'Out' 17
Monaco has a reputation for buying in talent from elsewhere and selling them on for huge sums after a couple of seasons - see Radamel Falcao and James Rodriguez.
But they also produce more than their fair share of their own future stars. One of which - Anthony Martial - could end up Manchester United almost £60 million if he fulfills his potential.
= 8 | Arsenal | Total - 22 players | 'In' - 9 | 'Out' 13
Arsene Wenger's faith in youth is well-renowned, and sometimes the cause of frustration amongst Gooners. But it is clearly paying dividends, if not always for the north London club themselves.
Alex Iwobi and Hector Bellerin are part of the latest generation, whilst the likes of Cesc Fabregas and even lesser success stories likes Sebastian Larsson remain in the Premier League.
7 | Roma | Total - 24 players | 'In' - 3 | 'Out' 21
Roma's 3-21 ratio probably won't please fans in the Italian capital.
However, whilst the Serie A club does continue to provide stars for clubs across Europe, Roma's supporters can take solace in the fact they have enjoyed the full careers of club legends Francesco Totti and Daniele De Rossi.
= 5 | Real Sociedad | Total - 25 players | 'In' - 16 | 'Out' 9
When talking about Sociedad's youth products you could name just two former players - Xabi Alonso and Antoine Griezmann - and they'd still rank highly in terms of quality.
Perhaps more impressive, though, is the fact that they are currently riding high in 6th in La Liga with 16 home grown players in their squad.
= 5 | Athletic Bilbao | Total - 25 players | 'In' - 17 | 'Out' 8
Like Sociedad, Bilbao's current squad is made up largely of players they themselves have produced.
Of course, given that the Basque club are hell bent on only signing players brought up in the region, it makes sense. It's also a pretty good way of making money too, as shown by the sales of the likes of Ander Herrera to Man United.
4 | Lyon | Total - 29 players | 'In' - 12 | 'Out' 17
Lyon remain one of the top teams in France, and one of the best environments to develop the nation's top talent apparently.
Their biggest home grown talent right now is Alexandre Lacazette, the striker Arsenal seem to have been linked to for half a decade.
3 | Manchester United | Total - 34 players | 'In' - 6 | 'Out' 28
United's famous youth academy continues to provide stars for Jose Mourinho - Marcus Rashford and Jesse Lingard being the two most obvious candidates.
They do, though, tend to sell on their youngsters. A policy that, in the case of Paul Pogba, cost them a world record transfer fee this summer.
2 | Barcelona | Total - 37 players | 'In' - 7 | 'Out' 30
Barcelona's La Masia youth system has brought through some of the best players currently playing the game - see Lionel Messi, Andres Iniesta and Gerard Pique - but they no longer top the list as the most prolific academy on European football.
1 | Real Madrid | Total - 41 players | 'In' - 7 | 'Out' 34
Usually considered the bigger spending club when compared to their rivals, Real actually provide four more players across the top five European leagues than Barcelona.
Like United, though, they too were forced to spend big to bring back one youth product, Alvaro Morata, this summer.
Do YOU want to write for GiveMeSport? Get started today by signing-up and submitting an article HERE: https://www.givemesport.com/writeforgms