RT Journal Article T1 Analysis of elite soccer players’ performance before and after signing a new contract A1 Gómez Ruano, Miguel Ángel A1 Lago Peñas, Carlos A1 Gómez López, María Teresa A1 Furley, Philip K1 2411.06 Fisiología del Ejercicio K1 6109.07 Evaluación del Rendimiento AB 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. PB PLoS ONE SN 19326203 YR 2019 FD 2019-01-25 LK http://hdl.handle.net/11093/3705 UL http://hdl.handle.net/11093/3705 LA eng NO PLoS ONE, 14(1): e0211058 (2019) NO Ministerio de Economía y Competitividad | Ref. DEP2016-75785-R DS Investigo RD 25-abr-2025