1. Introduction and Overview. 2. Detecting Influential Observations and Outliers. 3. Detecting and Assessing Collinearity. 4. Applications and Remedies. 5. Research Issues and Directions for Extensions. Bibliography. Author Index. Subject Index.

Regression Diagnostics: Identifying Influential Data and Sources of Collinearity

The aim of the current study was to analyse performance differences of football players 2-years prior and the year after signing a new contract (the following year) while taking playing position, nationality, player's role, team ability, and age into account. The sample was comprised of 249 players (n = 109 defenders, n = 113 midfielders; and n = 27 forwards) from four of the major European Leagues (Bundesliga, English FA Premier League, Ligue 1, and La Liga) during the seasons 2008 to 2015. The dependent variables studied were: shooting accuracy, defense (the sum of defensive actions, tackles, blocks, and interceptions), yellow cards, red cards, passing accuracy, tackle success, and minutes played per match. Two-step cluster analysis allowed classifying the sample into three groups of defenders (national important, foreign important, and less important players) and four groups of midfielders and forwards (national important, foreign important, national less important, and foreign less important players). Magnitude Based Inference (MBI) was used to test the differences between player's performances during the years of analyses. The main results (very likely and most likely effects) showed better performance in the year prior to signing a new contract than the previous year for foreign important defenders (decreased number of red cards), national important midfielders (increased number of minutes played), foreign important forwards (increased minutes played and defense), and national important forwards (increased minutes played). In addition, performance was lower the year after signing the contract compared to the previous one for less important defenders (decreasing defense), national less important midfielders (decreased minutes played), and foreign less important forwards (decreased defense). On the other hand, the players showed better performance in defense and more minutes played the year after signing the contract for less important defenders, national less important midfielders, and foreign less important forwards. These results may assist coaches to decide on when a new contract should be signed or the duration of the contract.

/pdf/analysis-of-elite-soccer-players-performance-before-and-1q3q3n9s5n.pdf

Analysis of elite soccer players' performance before and after signing a new contract.

Purpose


The Union of European Football Associations (UEFA) legislative intervention around “home-grown” player quotas came into effect for the 2006-2007 season, aiming to protect playing opportunities and the development of indigenous talent. Previous research has identified clear differences between clubs and club types regarding opportunities for academy players. This paper aims to examine the outputs from six European leagues (France, Germany, Italy, The Netherlands, Spain and England), identifying differences between national associations, club type, and on an individual club level. The paper investigates different league structure (in terms of allowing reserve teams in the professional leagues) and assesses UEFAs legislation in relation to programme theory (expected outcomes).




Design/methodology/approach


The study is based on playing data from 200 clubs and 3,329 indigenous players making their debut in one of the six leagues since 2006, and includes ten seasons of competition to 2015-2016.




Findings


The number of players produced and playing opportunities offered since 2006 are more prominent in the Spanish, The Netherlands, French and German leagues compared to Italy and England. For those clubs competing in all ten seasons, a similar pattern emerges with those four nations producing greater outputs. Four clubs significantly outperform others in terms of producing players reaching any top-six league first team, and for their own academy graduates. Additionally, the four leagues allowing reserve teams in their professional structure have a higher level of “output” for their academy players.




Originality/value


The paper discusses issues in the design of the legislation (not making nationality a factor and being unable to control other dominant variables) as key weaknesses to influencing change, and achieve the rationale cited by UEFA for its introduction.

/pdf/measuring-player-development-outputs-in-european-football-3s9w9e7cx6.pdf

Measuring player development outputs in European football clubs (2005-2006 to 2015-2016)

A growing literature examines adverse behavior as unintended consequences of incentives. We test Lazear’s hypothesis that states that if rewards were dependent solely on relative performance then an increase in rewards would induce agents to engage in sabotage activity to reduce rivals’ output. We test this hypothesis using the natural experiment of a rule change in Spanish football, the increase in points for winning a league match from two to three. We find, consistent with Lazear’s hypothesis, that teams in a winning position were more likely to commit offences punishable by dismissal of a player after this change.

The Effect of Incentives on Sabotage: The Case of Spanish Football

The policy of using foreign players and their impact on club success is still relevant and can be viewed from multiple angles. This article focuses on the impact of the proportion of foreign players’ appearances on the success of football clubs in their home leagues, as well as in European competitions. The research is focused on the most successful European clubs over the last ten years. A total of 19 European clubs were selected for research purposes, which resulted in 190 cases. Statistical tests, correlation, and regression analysis were used for their verification. The research shows that there is a dependence between the appearances by foreign players in matches and the success of clubs in domestic and European competitions. Furthermore, the trend of higher use of foreign players compared to domestic players was also proved. The presented research provides a different perspective on the issue, attributing greater importance to the appearances by players in matches compared to other studies, considering only the total number of foreign players.

https://www.mdpi.com/2071-1050/12/1/264/pdf

Impact of the Proportion of Foreign Players’ Appearances on the Success of Football Clubs in Domestic Competitions and European Competitions in the Context of New Culture

This study contributes to research on migrant pay disparities by analysing the impact of players' domestic/foreign status on performance-based pay offered to professional footballers, to understand if foreign players benefit from a preferential labour market. We used information from publicly available data of 275 footballers who played for two consecutive seasons in the Italian league Serie A. We found that the relationship between previous and current performance was partially mediated by the current salary. This result reinforced earlier findings on the pay-performance relationship, where seasonal performance is particularly relevant. Moreover, our results show that pay discrimination does not indicate a straightforward (dis)advantage for one group, but presents a more complex picture. We have examined possible underlying reasons for these disparities and offered suggestions for further research. We conclude by discussing how clubs and managers could consider incentives to strengthen pay-performance relationships by being sensitive to the complex influence of players' origins.

William Legeais

Papers

Do Italians Really Do It Better? Evidence of Migrant Pay Disparities in the Top Italian Football League