These vacancies are still available and the office location is flexible for both roles. Commute.… 22 Jun

BLOG: Tramite i dati Opta relativi alle catene di passaggi, @Dtrombetta87 profila le diverse tipologie di terzini n…… 21 Jun

BLOG: Using the Opta sequence framework, @Dtrombetta87 profiles the different types of full-back in Serie A last se…… 19 Jun

OptaPro #WorldCup analysis – this latest player profile focuses on Morocco’s Amine Harit. Creator.… 15 Jun

During this episode, Head of OptaPro @BenMackriell shares insight on the role of analysts during international tour…… 15 Jun

The OptaPro Blog

RSS Feed

Welcome to the OptaPro blog, featuring news and analysis from OptaPro's cutting-edge research team.

GUEST BLOG: Player turnover - Best practices at big-5 league level by Raffaele Poli

Raffaele Poli, Head of CIES Football Observatory

The hectic schedule of football competitions implies that player turnover is a hot topic in the professional game. This paper compares strategies followed by big-5 league clubs according to their last season's results and allows us to highlight best practices in this area.

In order to effectively carry out this study, the teams of the five major European championships are divided into four tiers according to their sporting level. This is measured through the CIES Football Observatory coefficient - a calculation that combines the percentage of points won in European club competitions during the last five seasons by the representatives of a national association and the number of points per match obtained by teams in their respective championships during the 2011/12 season.

The coefficient thus allows us to determine four club tiers, of which the first one for the 2011/12 season is composed of the following teams: Real Madrid, Manchester United, Manchester City, Barcelona, Borussia Dortmund, Juventus, Bayern Munich, Tottenham and Arsenal.

Results presented in this paper are part of the CIES Football Observatory Annual Review 2012 that will be officially launched in August. The specific section on player pitch performance is already available by pre-ordering the full study. For more information see or write to

How to measure player turnover?

Player turnover may be measured in different ways. A first indicator is the overall number of players fielded during the season. As for the English Premier League, more and more championships are introducing squad size limitations. The analysis of the number of players used according to the sporting level of clubs is thus very interesting also from a game governance perspective.

A second indicator we can use to measure player turnover is the cumulated percentage of minutes played from the most to the least fielded footballer. This statistic complements to the previous one insofar as it enables to compare the distribution of minutes among first team squad members and to highlight to what extent coaches rely on a core group of key players. The average percentage of minutes played by the most fielded players can also be used for the same purpose.

A third pertinent indicator refers to the average number of changes in the starting 11 decided by club managers from one championship match to the next one. While injuries  are a major factor in influencing coaches' decisions, it also allows us to  see any alterations that managers make on a game by game basis.

A fourth indicator is the overall number of different line-ups used by managers during the season. Again, this enables us to understand to what extent managers rotate players on the pitchand is ideally complemented by a fifth indicator that tracksthe number of minutes played using these different line-ups.Players fielded

None of last season's big-5 league champions fielded more than 25 players. Moreover, none signed more than three footballers during the last winter transfer window. This shows that regardless of the existence of squad size limitations, the best performing clubs tended to be fairly parsimonious in the overall number of players fielded. All title winners figure among the five clubs having utilised the least players in their respective league. No big-5 league club has used as few players as German Bundesliga and Champions League runner-up Bayern Munich (21).

Figure 1: overall number of players used by big-5 league champions (season 2011/12)


Tier 4 teams have on average fielded almost two more players that Tier 1 clubs (28.3 compared to 26.4). This confirms that having a large first-team squad does not naturally result in success. Conversely, the over-use of players tends to exert a negative impact on club results. From this perspective, the over-activity on the transfer market can be seen a sign of future difficulties even more than as the consequence of poor past results.

Figure 2: overall number of players used during the season, per big-5 league club tier (season 2011/12)



Percentage of minutes of the most fielded players

The percentage of minutes played by the 11 most fielded footballers out of the total minutes played by all squad members was always greater among big-5 league champions than for second ranked clubs. The average percentage of minutes played by the four most used defensive and offensive players was also greater for title winners than for the runners-up . The minimal value for a title winner was 73.2%.

This finding confirms the importance of having a core group of players on whom to count for all occurrences. It also allows to highlight the negative impact that injuries can have on results. While the effects of a long term injury on the squad as a whole are mostly unpredictable, it is noticeable that injuries  have negative consequences  for those teams that have arguably 'like for like' substitutes. This holds particularly true for defensive positions.

For all 2011/12 champions except Borussia Dortmund, the average percentage of minutes played by the four most fielded defensive players (not including goalkeepers) was greater than for the four most fielded offensive footballers.

Figure 3: average percentage of minutes played by the four most used defensive and offensive big-5 league champions' players (season 2011/12)


Generally speaking, the best performing clubs rely more than any other team on a core group of players to make up their line-ups. The five most fielded players in Tier 1 teams have played 40% of the total minutes played by all squad members. This figure goes progressively down in parallel with the sporting level of the clubs. The fifteen most fielded Tier 1 club footballers played almost 90% of total minutes (compared to about 83% for Tier 4 teams).

Figure 4: cumulated percentage of minutes played by the 5, 10 and 15 most fielded footballers, per club tier (season 2011/12)


Changes per match

During last season, all title winners also changed fewer players in the starting eleven than runner-up teams (the only exception is Manchester City , who used exactly the same number of players as Manchester United). The wealthiest clubs among champions changed more players on average than the poorest ones. While Real Madrid changed on average almost three players from one match to the next, this figure is one third lower for German champions Borussia Dortmund.

Figure 5: average number of changes in the starting 11 from a championship match to the successive one for big-5 league champions (season 2011/12)



However, the analysis by club tier shows that the best performing teams tend to change more players in the initial line-up than those performing least well. This is probably due to their participation in European cup competitions, as well as the presence in the squad of more players with a similar sporting level. This strategy is also probably related to the attempt of preventing injuries that can prove to be extremely detrimental from a longer term perspective. However, it must be noted that the gaps recorded are not statistically significant.

Figure 6: average number of changes in the starting 11 from a championship match to the successive one, per club tier (season 2011/12)


Different line-ups fielded

Four champions out of five are in the last five positions of their league ranking concerning the number of different  line ups fielded over the course of the season. The only exception is Manchester City. The team coached by Roberto Mancini fielded 138 different line-ups, the highest figure in the English Premier League (+20 compared to Manchester United). In all other cases, league winners used fewer formations than runner-up teams.

Figure 7: overall number of formations fielded over the course of the season by big-5 league champions (season 2011/12)


By club tier, while the differences are not very marked, the best performing clubs also used fewer different line-ups during the 2011/12 season than lower tier teams. This tends to confirm that too many changes to a starting line-up are detrimental to success and that it is worth trusting players even in difficult situations. The figures appear to indicate that clubs run by managers who are more resistant to panic are in a better position to maintain good performance levels over the long term.

Figure 8: overall number of formations fielded over the course of the season, per club tier (season 2011/12)


This result is reinforced by the data on the percentage of minutes played by the most used formations. The five most fielded Tier 1 club line-ups have on average played 22.4% of total minutes, a greater figure than for any other team tier. The positive gap is also to be found for the 10th (34.3%), 25th (61.3%) and 50th (82.5%) most used line ups.

Figure 9: cumulated percentage of minutes played by the 5, 10, 25 and 50 most fielded player combinations, per club tier (season 2011/12)


Best practices

While they use fewest players over the course of a season and rely more on core group of key players, the best performing clubs tend to change more players in the starting 11 from one match to the next. However, during last season, winning teams also averagely changed fewer footballers than runner-up clubs.

These findings suggest that the best solution is to have seven to eight stable players in the line-up, plus six to eight interchangeable players. In this way, clubs are able to maintain stability and cohesion, while preserving the physical capital of footballers playing in the positions where freshness is particularly important (mostly offensively).

Irrespective of club wealth, our analysis suggests that it is recommended that clubs concentrate financial efforts on a core group of players instead of increasing the number of first team members at all costs. In other words, quality is worth more than quantity. While the requirement to have competitive substitutes  plays a part  in achieving a competitive advantage held by the best performing clubs -above all when it comes to replacing long-term injured players - evidence shows that the real difference is made by a relatively low number of players (around 16 per season).

This is also illustrated by the fact that all 2011/12 champions have at least seven players who are present in each of the three most used line-ups. This figure is up to nine for Juventus, Borussia Dortmund and Manchester City. The latter club is the only title winner where the three most fielded line-ups do not include the same defenders. From a success perspective, this clearly confirms the importance of reducing player turnover in defence as much as possible.

Other findings that are found in the 2012 CIES Football Observatory Annual Review show that clubs run by patient managers have a key competitive advantage compared to teams run by impulsive ones. Indeed, cohesion and routines are crucial for success in football. Statistical evidence shows that it is worth trusting players even in difficult situations. Of course, this advice is easier to follow when club results are satisfactory. However, in all cases, an ability to manage the squad using  a mid- to long-term perspective, follow a coherent strategic line and to resist to media and popular pressure are key success factors.

The main reason is probably that this will favour the creation of a positive context where players more easily understand the specific role that they are called on to play. This will enhance their motivation to fully adhere to the sporting project of their employer club which, in turn, puts them in the best condition to continuously perform at their highest level possible. Many examples show that top level performances are by far not only related to the players' intrinsic talent, but also to the general environment of a team.


Poli R., Besson R., Ravenel L. 2012: CIES Football Observatory Annual Review, CIES, Neuchâtel.

Posted by Raffaele Poli at 09:26


Post a comment