The study reviews U23 players currently present in 31 top division leagues in Europe. Footballers are ranked according to the level of experience gained since the start of their career at adult level. Among players listed, notably are two goalkeepers who were born in 1999: Gianluigi Donnarumma (Milan) and Alban Lafont (Toulouse).

The method of experience capital allows clubs to optimise their approach regarding transfers by considerably reducing the risks inherent in such operations, from both the sporting and economic point of view. For recruiting clubs, there is indeed no better guarantee than recruiting footballers who have had the opportunity to play as often as possible at the highest possible level taking into account their age and talent.

Our research team is at the service of clubs interested in finding out more about the practical modalities of implementing a talent spotting system of this kind.

The English Premier League does not only gather the highest percentage of foreign players (see the 12th edition of the CIES Football Observatory Monthly Report), but it is also that where the most footballers were recruited from abroad: 43.1%. This percentage is only 31.2% for the French Ligue 1, while the big-5 league average is 36.5%.

The clubs per league who signed the highest proportion of their current squad members from foreign teams are Chelsea (75.0%), Monaco (73.1%), Lazio (67.9%), Sevilla (64.3%) and Bayern Munich (54.2%).

In total, 23 teams big-5 league teams out of 98 recruited at least half of their first team players from abroad: eight in England, five in both Spain and Italy, three in Germany and two in France. The data for all clubs is available in issue number 144 of the CIES Football Observatory Big-5 Weekly Post.

Since last June, Didier Deschamps has fielded 35 footballers who played during the current season in the big-5 leagues (34 for England). So far, they have on average played 1,913 domestic league minutes, which is about 21 matches per player. These figures are 1,585 and 17 for English national A-team players.

Up until now, the employer clubs of big-5 league players fielded by France have achieved 1.72 points per match. The highest value was recorded for teams of Spanish internationals (1.95), ahead of clubs employing footballers representing Germany (1.79) and Italy (1.77). On average, teams of English internationals achieved so far 1.61 points per match. This is only the 9th highest level among teams qualified.

The figures for all countries are available in issue number 143 of the Big-5 Weekly Post. For more information, the 11th CIES Football Observatory Monthly Report presents the squad profile of the 50 most competitive national A-teams at worldwide level. It notably shows that England fielded the youngest players in 2015 at European level.

The second coach with the longest stay at the head of his current club is Christophe Galtier at St-Etienne: 75 months. At the top of the tables in the other leagues are Giampiero Ventura (Torino, 57 months), Diego Simeone (Atlético Madrid, 51 months) and Markus Weinzierl (Augsburg, 45 months).

The median values per league vary between 16 months in the French Ligue 1 and only 9 months in the Italian Serie A. In the latter country, it is not unusual that clubs change many coaches during the same season. This reflects the lack of strategic vision of club officials more than any form of incompetence of coaches.

Between 1st July 2009 and 31st December 2015, footballers who did not yet celebrate their 22nd birthday played 14.6% of domestic league minutes in 31 top divisions throughout Europe. This percentage varies from 28.7% in Croatia to 6.1% in Cyprus. The highest value at big-5 league level was observed in the German Bundesliga (14.5%). This is almost twice as much as in the English Premier League and the Italian Serie A (7.5%).

At club level, the highest figures for teams always present in the top division league of their country during the period analysed were measured for Lokomotiva Zagreb (54.2%), OFK Belgrade (43.0%) and Feyenoord Rotterdam (39.8%). The record level in the big-5 was registered for Schalke 04 (25.0%), ahead of Toulouse (24.2%) and Bayer Leverkusen (20.7%). The record value in the English Premier League was at Liverpool (14.7%).

The Report also presents the lowest values of minutes played by U22 national footballers. AEL Limassol fielded young nationals for the fewest percentage of minutes (0.2%), followed by Stoke City and Juventus (both 0.4%). This figure was very low also at Chelsea (0.5%) and Manchester City (1.4%). Many other teams recently qualified for the Champions League are not concerned about giving young nationals their chance: Naples, Rome, Zenit, Fenerbahçe, Porto, etc.

Issue number 141 of the Big-5 Weekly Post presents the most experienced players born in or after 1995. Experience is calculated on the basis of domestic league matches played since the start of the career at adult level, weighted according to the sporting level of employer clubs. For more information about the experience capital approach exclusively developed by the CIES Football Observatory research team, please refer to the second edition of the Monthly Report.

Six players born in 1997 employed by clubs outside the big-5 leagues have a greater experience than any footballer born in the same year playing in the five major championships: Rúben Neves (Porto), Youri Tielemans (Anderlecht), Breel Embolo (Basle), Enes Ünal (NAC Breda, on loan from Manchester City), Ante ?ori? (Dinamo Zagreb) and Renato Sanches (Benfica). Sooner or later, they all should be able to settle in the most competitive leagues.

The top-10 tables for both players in the big-5 leagues and outside the five major European championships are presented in issue number 141 of the Big-5 Weekly Post. More information is available on request.

Francesco Totti is the big-5 league player who has been for the longest period in the club where he made his debut. The 39 year-old Italian is playing his 24th season at Rome. Conversely, his former teammate both at Rome and in the Italian national team Luca Toni already played for 15 clubs over his career. Both players were in the starting line-up of the 2006 World Cup final won against France.

The youngest player among the 28 big-5 league footballers who played for 10 or more clubs since the beginning of their professional career is the new Newcastle United signing Andros Townsend. While only aged 24, the English international already played for 11 teams: Tottenham Hotspur, Yeovil Town, Leyton Orient, Milton Keynes Dons, Ipswich Town, Watford, Millwall, Leeds, Birmingham City, Queens Park Rangers and Newcastle United.

The full lists are available here.

Overall, the current squad member of a big-5 league club who played the most domestic league games during his career is Leicester City’s goalkeeper Mark Schwarzer: 626 matches. Two other goalkeepers have already played more than 600 championship games over their career: Gianluigi Buffon (Juventus) and Kelvin Davis (Southampton).

Cristiano Ronaldo is second among players born in 1985 behind Bournemouth’s Simon Francis and ahead of Wayne Rooney. The top-3 tables are available in issue number 139 of the CES Football Observatory Big-5 Weekly Post. The analysis includes B-team matches.

The players listed below head the ranking for their age group.

Born on 1996 or after
Dele Alli, Tottenham, 98 matches
Born on 1995
Samu Castillejo, Villarreal, 129 matches
Born on 1994
Nathan Redmond, Norwich, 163 matches
Born on 1993
Romelu Lukaku, Everton, 210 matches
Born on 1992
Koke Resurrección, Atlético Madrid, 236 matches
Born on 1991
Eden Hazard, Chelsea, 277 matches
Born on 1990
James McCarthy, Everton, 295 matches
Born on 1989
Charlie Austin, Southampton, 320 matches
Born on 1988
Sergio Agüero, Manchester City, 368 matches
Born on 1987
Billy Jones, Sunderland, 395 matches
Born on 1986
James Milner, Liverpool, 410 matches
Born on 1985
Simon Francis, Bournemouth, 460 matches
Born on 1984
Wes Morgan, Leicester, 527 matches
Born on 1983
Jon Walters, Stoke City, 456 matches
Born on 1982
Rickie Lambert, West Bromwich, 597 matches
Born on 1981
Gareth Barry, Everton, 588 matches
Born on 1980
Sylvain Armand, Stade Rennais, 522 matches
Born on 1979
Massimo Maccarone, Empoli FC, 539 matches
Born on 1978
Gianluigi Buffon, Juventus, 612 matches
Born on 1977 or before
Mark Schwarzer, Leicester City FC, 626 matches

The U21 footballers listed below have played the highest percentage of minutes per position. Among them are notably two Schalke 04 players: Leon Goretzka and Maximilian Meyer. The latter footballer outranks his teammate Leroy Sané among attacking midfielders. The full tables are available here.

Goalkeepers

Gianluigi Donnarumma (Milan), born in 1999, 68.0%

Centre backs

Niklas Süle (Hoffenheim), born in 1995, 100.0%

Full backs

Héctor Bellerín (Arsenal), born in 1995, 92.3%

Defensive midfielders

Leon Goretzka (Schalke 04), born in 1995, 82.5%

Attacking midfielders

Maximilian Meyer (Schalke 04), born in 1995, 78.8%

Forwards

Anthony Martial (Manchester United/Monaco), born in 1995, 89.6%

The biggest performance gap was measured between Real Madrid and Rome: +32%. Atlético Madrid and Bayern Munich also performed significantly better than PSV Eindhoven and Juventus: +25%, respectively +23%. Manchester City and Barcelona outperformed Dinamo Kiev and Arsenal by 11%, while the performance level of Chelsea was 10% higher than that of Paris St-Germain.

According to the analysis of the CIES Football Observatory, the matches with the most uncertain outcome will oppose Gent and Wolfsburg (+3% for the Belgian club), as well as Benfica and Zenit St-Petersburg (+6% for the Portuguese side). Data used for the present research were provided by OptaPro. Click here for more information about the approach of the CIES Football Observatory for sustainable success.

Foreign players are much more numerous in Europe (47.7% of squads) and in the MLS (48.5%) than in Asia (17.9%) and South America (13.6%). Great discrepancies also exist according to position. While foreign footballers account for 34.9% of forwards, they only represent 20.5% of goalkeepers. The relative presence of foreign players among defenders and midfielders is around 25%.

From an age perspective, foreign footballers in the leagues studied are on average older than nationals: 27.1 years compared to 25.7. While only 13.2% of U21 footballers are foreigners, the latter represent 33.8% of players over 28 years of age. Nevertheless, the average age of first migration tends to diminish in relationship with the international recruitment of a greater number of very young players.

In six European leagues surveyed, more than half of teams are made up of foreign players: England, Belgium, Italy, Turkey, Portugal and Germany. At the opposite end of the spectrum, foreign players account for less than 10% of squads in Brazil, Uruguay, Venezuela, Costa Rica, Colombia, Argentina, Paraguay, Uzbekistan and Iran.

The study also warns the wealthiest clubs against the risk of abandoning the training of local players in favour of their import. The Report reminds that “all the clubs having left their mark on modern football in Europe (Real Madrid, Ajax, Bayern Munich, Milan, Manchester United, Barcelona) and elsewhere (Boca Juniors, River Plate, Santos, Flamengo) had several home-grown pillars, whose presence made a major contribution to their legendary status”.

The Report concludes that “talented players are born all over the world. What is missing in the first instance, is not so much talents, as a favourable context for their development. So as to encourage clubs worldwide not to take the easy road and fall into the trap of recklessly importing players and selling their souls to the market actors, training must be better protected and better paid”.

In 34 cases out of 49, the gap between the fee invested to recruit a big-5 league player and his estimated transfer value was less than 2 million €. The strong correlation between fees paid and predicted (76%) confirms the accuracy of the algorithm created from the analysis of more than 1,500 paying fee transfers occurred since 2010.

Our study allows us highlighting the payment of much higher or, more rarely, lower transfer compensations than fees paid in the recent past for players with similar characteristics. The inflation in transfer costs compared to the 11 previous transfer windows was 28%.

According to our estimates, the most over-paid player was Jackson Martínez: 42 million € instead of 18.2 (+23.8 million €). Among the five most over-paid footballers are another player transferred to China, Ramires (+10.8 million €), as well as three footballers signed by English Premier League clubs: Lewis Grabban (+7.8 million €), Timm Klose (+7.5) and Andros Townsend (+7.0).

The most under-paid player was also transferred between Premier League clubs: Jonjo Shelvey. According to our analysis, while the transfer value of the young English national A-team midfielder was 30.9 million €, Newcastle was able to sign him for "only" 16 million € (-14.9). The transfers of Mario Suárez to Watford and Augusto Fernández to Atlético Madrid were also cheaper than expected.

The figures for all big-5 league footballers transferred for money in January is available in issue number 136 of the Big-5 Weekly Post. For more information about the CIES Football Observatory approach, please refer to Monthly Reports number 6 and number 7. A transfer value calculator for big-5 league players is also freely available online.

Previous research from the CIES Football Observatory suggests that sticking on a core group of footballers often allows clubs obtaining top level results. No team who heads the table in its respective league used more than 24 players. This figure is 20 for Napoli, 22 for Leicester and Bayern Munich, 23 for Paris St-Germain and 24 for Barcelona.

Conversely, frequent line-up changes tend to reflect anxiety which is detrimental to the improvement of results. So far, clubs at the bottom of the table in their respective league on average fielded 26.0 players. This figure is 22.2 for clubs heading the table, 23.6 for the top three ranked teams per league and 25.3 at big-5 league level.