Effects of VAR on the Effective Playing Time in Chinese Super League

Utilizing statistics from matches before and after the integration of the Video Assistant Referee(VAR) system in the Chinese Super League(CSL), this study investigated how the adoption of VAR impacts the effective playing time in the CSL. By means of a quantitative regression model, it was revealed that, while keeping other factors constant, the introduction of VAR led to an average increase of 2.39 minutes in effective playing time per game, corresponding to a 2.00% rise in effective playing time proportion. We concluded that the incorporation of VAR triggered alterations in the conduct of involved parties, consequently contributing to the extension of effective playing time. This phenomenon is attributable to four key mechanisms: VAR reduces the time spent on contentious incidents, minimizes covert fouls, VAR-induced stoppages result in visual effects, prompting organizers and referees to pay heightened attention to stoppage time, subsequently leading to an augmentation in injury time. This increase in injury time discourages teams from employing an intentional stalling tactic. Evaluating specific mechanisms through regression analysis indicated that, following the implementation of VAR, both the fouls per game and the red cards and yellow cards notably declined. The utilization of VAR resulted in an average extension of 0.94 minutes in injury time. Nevertheless, in cases where matches exhibited lower levels of suspense, namely when the goals-scored difference is above one, the duration of injury time substantially decreased. These findings underscore that, with regards to the CSL, the introduction of VAR positively affects the conduct of involved parties through a range of mechanisms, culminating in a favorable impact on effective playing time. Moreover,post-VAR introduction, referees display a heightened inclination to prolong injury time, effectively offsetting stoppage time during standard play, thus enhancing the spectator experience. Furthermore, this form of officiating deters leading teams from excessively employing time-wasting tactics, thereby contributing to the enhancement of the league's quality and the spectator experience.