Age categories in youth football are generally defined from January 1st onwards. Issue number 345 of the CIES Football Observatory Weekly Post analyses the month of birth of 43,938 players fielded in 2021 in 119 leagues worldwide. The study confirms the relative age effect, i.e. the advantage to be born early in the year to make a career.

Issue number 344 of the CIES Football Observatory Weekly Post lists the 100 footballers worldwide who did not yet celebrate their 20th birthday and gained the most experience in official senior matches over the course of the year (minutes weighted by sporting strength of employer clubs or competitions played). The FC Barcelona’s gem Pedri González is clearly at the top of the table ahead of Mason Greenwood (Manchester United), Nuno Mendes (Sporting CP) and Ryan Gravenberch (Ajax).

With the start of a new and exciting season, the CIES Football Observatory is delighted to disclose some of the exclusive player physical data produced by our fresh partners SkillCorner. The French company has developed a unique and automated approach to track players from any football broadcast, whilst generating physical data and continuous XY tracking via specialised algorithms. With over 40 competitions covered worldwide, they position themselves as leaders in the market.

How much did players selected for the upcoming Euro 2021 play since the COVID break in 2020? Issue number 342 of the CIES Football Observatory Weekly Post ranks the footballers according to minutes played in official games for both clubs and national teams (A-teams and U21) since the 16th May 2020. With 6,472 minutes and 81 matches, Manchester United’s and Portugal Bruno Fernandes heads the table.

Three English talents are at the top of the biannual ranking of the greatest estimated transfer values for big-5 league players. According to the CIES Football Observatory algorithm, €190 million should be proposed to eventually convince Manchester City releasing Phil Foden. Two Manchester United’s players complete the podium: Mason Greenwood (€178 M) and the former leader Marcus Rashford (€159 M). The top 100 is available in the 341st Weekly Post.

National teams with players active in the most competitive clubs have greater chances to win trophies. Issue number 340 of the CIES Football Observatory Weekly Post compares selections qualified from the perspective of the average sporting level of the teams of employment of players in squads. France tops the table ahead of Germany and Spain.

With the five major European leagues ended, issue number 339 of the CIES Football Observatory Weekly Post presents the best line-ups for each championship. Players were selected according to the CIES performance index developed using data from OptaPro. Only footballers fielded for at least two thirds of domestic league minutes were included in the line-ups.

How frequently are teams fouling their opponents across Europe? Issue number 338 of the CIES Football Observatory Weekly Post answers this question using the data provided by InStat. At the level of the five major European leagues, the lowest foul frequency was measured for Arsenal (one foul every 10’44”), while Getafe is at the bottom end of the table (one foul every 5’44”).

Issue number 337 of the CIES Football Observatory Weekly Post reveals the employment rate of club-trained footballers (i.e. those having been for at least three seasons between the ages of 15 and 21 in their employer club) in teams from 27 top divisions of UEFA member associations. The highest percentage of minutes by club-trained players overall was recorded for the Slovakian side MŠK Žilina (61.5%), while RC Celta de Vigo (49.0%) has the greatest figure for big-5 league teams.

Issue number 336 of the CIES Football Observatory Weekly Post presents the index developed by the sports data company InStat to assess the performance of football players. This metric considers the technical gestures achieved by players, their playing time, as well as the level of the competitions in which matches were played. For footballers with more than 1,000 domestic league minutes this season, Lionel Messi (405) outranks Neymar Júnior (381) and Robert Lewandowski (371).

While player mobility has increased in recent years, squad stability remains a key success factor in football. Issue number 335 of the CIES Football Observatory Weekly Post highlights the footballers among current squad members having played the most domestic league matches during the last ten years for 540 teams from 35 top divisions worldwide. Sebastián Viera holds the record figure with 395 championship games for Junior de Barranquilla (Colombia).

The 334th edition of the Weekly Post presents the squad transfer value for the 98 teams in the five major European leagues. The estimated value for players loaned to other big-5 league teams was computed for the clubs of belonging, while that of players on loan outside of the top five European championships is not considered. The estimates were calculated through the CIES Football Observatory transfer value algorithm.