title: A topography of free kicks in soccer.
abstract: This study investigates the spatial relationship of performance variables for soccer free kicks. In order to suggest ways in which players might optimise their performance, we collected data from free kicks (<35 m to goal line) of two German Bundesliga seasons (2013/14, 2014/15) (n = 1624). In the analysis, we applied the ISO-map approach using colour gradients to visualise the mean values of a variable on a 2D-map of the pitch. Additionally, variograms were used to describe the degree of spatial dependence of the free kick variables. Results show that DENSITY, TYPE OF PLAY, PLAYERS IN WALL, DISTANCE TO WALL and RULE VIOLATION were strongly spatially dependent. Centrality and proximity to the goal increased the variables PLAYERS IN WALL, RULE VIOLATIONS and INTERRUPTION TIME, and the ratio of goals scored increased from 5.9% (central far) to 10.9% (central near). In 70.9% of the shots, players preferred a switched laterality, which did not result in a higher success rate. Furthermore, there was no statistical advantage for the defensive team when DISTANCE TO WALL was below 9.15 m or when there was a RULE VIOLATION. Crosses had a success rate (i.e., first controlled ball contact after the cross) of 20.8%. Played with natural laterality, they were 5% more successful than with switched laterality. Crosses from the right side outside the penalty box were 10% more successful than from the left side. Therefore, it might be worthwhile practising the defence of balls coming from this side.
authors.affiliation: a Department of Training Science and Sport Informatics , Technical University of Munich , München , Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Link
authors.affiliation: a Department of Training Science and Sport Informatics , Technical University of Munich , München , Germany.
authors.forename: Otto
authors.initials: O
authors.lastname: Kolbinger
authors.affiliation: b Deutsche Fußball Liga GmbH , Frankfurt , Germany.
authors.forename: Hendrik
authors.initials: H
authors.lastname: Weber
authors.affiliation: c Department of Biomechanics, Kinesiology and Applied Computer Science , University of Vienna , Vienna , Austria.
authors.forename: Michael
authors.initials: M
authors.lastname: Stöckl
mesh_terms: D054874:Athletic Performance; D003163:Competitive Behavior; D007839:Functional Laterality; D006801:Humans; D009048:Motor Skills; D009068:Movement; D012916:Soccer
keywords: Performance analysis; free kick; soccer; topography; variography