Issue number 185 of the CIES Football Observatory Weekly Post analyses the stability of squads in 31 top division leagues of UEFA member associations. The championships surveyed are compared according to the percentage of players who joined the first team squad of their employer team after January 1st 2016.

The presence of club-trained footballers greatly varies throughout Europe. Issue number 164 of the CIES Football Observatory Weekly Post ranks 31 top division championships of UEFA member associations according to the percentage of club-trained players in squads.

Issue number 163 of the CIES Football Observatory Weekly Post presents the annual list of the most productive training clubs. At the head of the rankings for big-5 league players is Real Madrid, while Dutch side Ajax tops the table for footballers in 31 top division European championships.

Real Madrid squad members were on average recruited at the age of 22.5 years. This is the lowest figure at big-5 league level. Issue number 162 of the CIES Football Observatory Weekly Post presents the data for the 98 clubs from the five major European championships. German and English teams are over-represented in the top positions of the rankings.

Issue number 161 of the CIES Football Observatory Weekly Post compares big-5 league teams according to the number of players in their current squad signed after January 1st 2016. The best performing teams recruited fewer footballers than the less competitive ones. German champions Bayern Munich only signed two players.

Issue number 160 of the CIES Football Observatory Weekly Post presents the percentage of domestic league minutes played by national footballers* since the start of the season. At the top of the table is Osasuna (97%), while Udinese is at the bottom (1%).