1. Introduction

In a collective sport such as football, where the whole is definitively more than the sum of its parts, optimal teamwork and cohesion are key ingredients for performance. To achieve sustainable success, consistent squad management is of fundamental importance. This Monthly Report illustrates the value of long-term planning for football clubs through the prism of squad stability.

The sample is composed of first team squad members present on the 1st of October in top division clubs from 31 UEFA member associations*. The period analysed stretches from 2009 to 2017. To be included, a footballer should have already played in domestic league games during the season of reference, or, if this was not the case, to have taken part in adult championship matches during each of the two previous seasons. The second and third goalkeepers were considered in all cases.

* [AUT] Austria, [BEL] Belgium, [BLR] Belarus, [BUL] Bulgaria, [CRO] Croatia, [CYP] Cyprus, [CZE] Czech Republic, [DEN] Denmark, [ENG] England, [ESP] Spain, [FIN] Finland, [FRA] France, [GER] Germany, [GRE] Greece, [HUN] Hungary, [ISR] Israel, [ITA] Italy, [NED] Netherlands, [NOR] Norway, [POL] Poland, [POR] Portugal, [ROM] Romania, [RUS] Russia, [SCO] Scotland, [SRB] Serbia, [SUI] Switzerland, [SVK] Slovakia, [SVN] Slovenia, [SWE] Sweden, [TUR] Turkey and [UKR] Ukraine

The indicator selected to measure the stability of teams is the percentage of players recruited by their employer club during the year of reference. Young footballers having joined the first team squad directly from the youth academy were not considered as new signings.

2. Comparative approach

During the period considered, the percentage of new signings in squads increased sharply from 36.7% to 44.9%. In 2017, a new record was observed in 11 of the 35 competitions studied: Belgium, France, Hungary, Israel, Norway, the Netherlands, Poland, Portugal, Russia, Sweden and Ukraine. This result reflects the acceleration of mobility in the footballers’ labour market. Consequently, the stability of squads is on the decrease.

​Figure 1: evolution in the % of new signings in squads, 31 European top divisions (2009-2017)​

The highest average percentage of players signed over the course of the year among squad members was recorded in Cyprus (57.7%). This proportion was above half in three other countries: Portugal (52.0%), Bulgaria (51.3%) and Serbia (51.0%). At the other end of the scale, the lowest percentages were observed in the three Scandinavian countries (Denmark, Sweden and Norway), as well as in the German Bundesliga. This finding reveals great differences in the cultural approach to football according to continental area.

​Figure 2: % of new signings, by league (2009-2017)​

The record percentage for new signings was recorded in 2009 for the Turkish side Diyarbakirspor: 96.4% of players present on the 1st October had been recruited during the year. The club was finally relegated. The team with the second highest figure, Neftochimic Burgas, also faced relegation at the end of the 2016/17 season. In general, as developed below, a high percentage of new signings reflects poor squad management and presages sporting difficulties.

​Figure 3: highest % of new signings, 31 European top divisions (2009-2017)​

The Finnish side FC Honka holds the record for the lowest percentage of new signings among first team squad members. In 2010, they finished fourth in the Veikkausliiga without any player with previous experience in adult leagues signed from other teams during the year. This is a unique situation for the leagues and seasons covered. Nations represented in the top ten are very different from those represented among the least stable clubs. The presence of Fenerbahçe SK is quite exceptional with respect to the generally high instability of Turkish clubs.

​Figure 4: lowest % of new signings, 31 European top divisions (2009-2017)​

3. Stability and success

The analysis of stability according to clubs’ sporting level reveals the existence of a general rule: the best performing teams have much more stable squads than the least competitive ones. As illustrated in Figure 5, the percentage of new signings decreases for each club sporting level category: from 42.4% for the least performing teams to 31.3% for the most competitive ones.

​Figure 5: % of new signings and sporting level of teams* (2009-2017)​* according to CIES Football Observatory coefficient

This finding highlights the relationship between stability and performance. It reflects the difficulties for teams with few financial means available to set up long-term squad planning. It also shows their tendency to over-speculate on the transfer market. This process often brings about a vicious circle of instability and poor results.

Apart from a lack of vision and resources, corruption is also an issue. As a considerable amount of money circulates through transfers, notably under the form of commission fees for intermediaries with close relationships with club officials, player trading may be easily directed towards personal profit rather than the sporting interest of teams.

As shown in Figure 6, clubs having won their league with the highest percentage of new signings are all situated in countries where squads are generally unstable. The only exception is Slavia Praha with respect to the Czech context. This club won the 2016/17 national league with more than a half of players recruited after the 1st of January 2016. This high transfer activity was linked to their takeover by a Chinese company.

​Figure 6: highest % of new signings, 31 European top divisions (2009-2017)​

Ludogorets is also an interesting case as they won the 2011/12 Bulgarian championship with more than nine new recruits out of ten squad members. Season after season, this team kept on winning the Bulgarian title and performing well in European Cup competitions. However, the percentage of new signings went progressively down to reach a record low of only one in five players for 2016/17.

Many clubs from the five major European championships are in the top ten table of champions with the lowest percentage of new signings for the season during which they won the league. Among countries hosting the big-5 leagues, only Italy has no representatives in this ranking. This reflects the overall greater mobility of players in the Peninsula compared to the other four main competitions. The lowest percentage of new signings overall was recorded at Bayern Munich for the 2016/17 season (9.1%).

​Figure 7: lowest % of new signings, 31 European top divisions (2009-2017)​

The average proportion of new signings among first team squad members for champions during the period considered was about one third (34.0%). This is 7.2% less than the figure measured for all teams in the leagues surveyed. This result confirms that clubs with a stable squad are at advantage. The record low was observed in the Spanish Liga (20.8%).

​Figure 8: average % of new signings for champions, per league (2009-2017)​

4. Conclusion

The study reveals the correlation between squad stability and success. The best performing teams have much more stable squads than lesser competitive ones. Between 2009 and 2017, big-5 league champions had on average only about one in four new players as squad members. This proportion can be considered as an optimal balance to achieve success.

The Report also highlights the increasing instability of teams across Europe. On the 1st of October 2017, 44.9% of players were recruited during the year. This figure was only 36.7% in 2009. If this trend continues, footballers who have been with their employer club for more than one year will soon represent less than half of squad members.

To limit the growing instability, football’s governing bodies should act against the increasing financial gaps between teams both nationally and internationally. They should also combat corrupt practices at both transfer market and club management levels. It is also necessary to limit the speculation around players’ mobility, notably through a greater protection of training clubs, the enforcement of the third-party ownership ban, as well as the reinforcement of the regulations regarding football intermediaries.