Author(s): HAMAMURA, R., TAZUKE, S., Institution: DOSHISHA UNIVERSITY , Country: GERMANY, Abstract-ID: 2106

INTRODUCTION:
In invasion games, players spend a large proportion of playing time without ball possession. Thus, off-the-ball movement, such as creating and exploiting space, is as important as ball-related skills. However, off-the-ball movement has mainly been assessed qualitatively, and quantitative methods remain insufficiently established. Previous studies developed the Game Test Situation (GTS “off-the-ball movement”), a task designed to elicit tactical behaviors common to invasion games. However, GTS has been used mainly for qualitative assessment, and its quantitative application has been limited. Moreover, the influence of task constraints, especially goal-oriented objectives, is understudied. This study aimed to examine task conditions suitable for quantitative assessment of off-the-ball movement.
METHODS:
Nineteen university students performed the GTS (three-on-three passing game) under two rule conditions with different winning criteria (rule A: number of successful passes; rule B: number of goals scored). Twelve games per condition were conducted with varying team configurations. Off-the-ball movement was evaluated from video recordings by GTS experts and classified as Good, Average, or Poor. Participants wore trunk-mounted accelerometers and Ultra-Wideband (UWB) positioning tags. Transfer entropy, an information-theoretic measure, was calculated from accelerometer data to estimate causal relationships between players’ movements. Based on this analysis, eight network-based indices were derived to quantify the amount and direction of information flow (incoming or outgoing) as well as its source (teammates or opponents). In addition, positional data obtained from the UWB tracking system were used to calculate five positional metrics: total distance, mean speed, speed SD, mean acceleration, and acceleration SD. Due to the small sample size of the Poor group, quantitative data were compared between the Good and Average groups.
RESULTS:
Under rule A, only the All-Path index was higher in the Good group (p < .01), while no significant differences were observed in the positional metrics. In contrast, under rule B, the In-Path and All-Path indices were higher in the Good group (p < .01), as were the InOut-Path, TeamIn-Path, and OppIn-Path indices (p < .05). Conversely, total distance, mean speed, speed SD, and acceleration SD were lower in the Good group (p < .05).
CONCLUSION:
Under the goal-oriented condition (rule B), the network indices indicated that Good players adjusted their movements in response to others, reflecting greater information inflow from teammates and opponents. Positional metrics suggested that these players exhibited more selective movement patterns, with lower total distance and reduced variability in speed and acceleration. Quantitative differences between qualitative groups were clearer under rule B. These findings indicate that goal-oriented game tasks are more suitable for quantitative assessment of off-the-ball movement in invasion games.