Porto general director Antonio Henrique has partially uncovered the mystery behind his club's efficient scouting organisation, which has enabled the likes of Anderson, Pepe, Deco and Hulk to leave the Portuguese giants for lucrative deals.
The Dragons have arguably one of the most successful scouting systems in place, in recent years, which has contributed to their profitable dealings in transfer windows, which most recently saw Hulk leave for Zenit St Petersburg for a reported €50 million.
"Porto's success rests on three assumptions: recruitment, development and yield," explained Henrique, speaking to France Football.
"Recruitment links with scouting, development is linked with training and productivity is linked with the performance of the player in the first team.
"Most players are young when they come to our club and end up being in training permanently."
Henrique also stressed the importance of extensive scouting, and explained how players are scrutinised before being invited to join the Portuguese giants.
He added: "We work with 250 scouts around the world in countries that make sense for football, because we will not send anyone to Bangladesh.
"We have internal and external scouts, which are divided into several levels of observation, which allows a player to be viewed by several people.
"They work with a shadow team, which is a set of players who are identified from various leagues, who are capable of being hired by Porto."