Zhang Bo, Lin Mingyuan, Qi Delihai, Zhang Liqing, Deng Pei
China Football College, Beijing Sport University, Beijing, 100084, China.
Sports Coaching College, Beijing Sport University, Beijing, China.
BMC Sports Sci Med Rehabil. 2025 May 29;17(1):135. doi: 10.1186/s13102-025-01192-5.
Even though the Chinese Super League (CSL) introduced Video Assistant Referees (VARs) in the 2018 season, it did not intervene in every game. The Hawthorne effect highlights how human behavior can change when individuals are aware they are being observed. VARs monitoring means VARs just introduces but does not intervene in the games. Thus, this research compared the performance in the games where VARs did not intervene and without VARs, to investigate whether VARs monitoring influences match performance, similar to the Hawthorne effect.
The sample includes matches in which VARs were not applied in the 2014-2017 season (n = 1920) and in which VARs were not intervened in the 2018-2021 season (n = 528). The Generalized Linear Mixed Model was used to examine the different variables in different groups.
The study found that after the implementation of VARs in the game, the percentage of non-intervention was 32%. Even though VARs was not applied, it had a significant impact on goals (p < 0.01, Cohen's d = 0.04), penalties (p < 0.001, Cohen's d = 0.07), free kicks (p < 0.001, Cohen's d = 0.18), tackles (p < 0.001, Cohen's d = 0.13), fouls (p < 0.01, Cohen's d = 0.11), and red cards (p < 0.001, Cohen's d = 0.04). Still, there were no significant differences in the number of shots, passes, corners, and yellow cards (p > 0.05). In addition, the effect size of all significant variables shows a small effect.
In the CSL, VARs intervene frequently in matches. VARs monitoring also had a measurable, albeit small, impact on sports performance, especially defensive performance. In addition, VARs monitoring follows the idea of FIFA to encourage attacking, and it also benefits limited fouls.
尽管中国超级联赛（中超联赛）在2018赛季引入了视频助理裁判（VAR），但并非每场比赛都进行干预。霍桑效应凸显了个体意识到自己被观察时，其行为会如何改变。VAR监测意味着VAR只是引入比赛但不进行干预。因此，本研究比较了VAR未干预的比赛和没有VAR的比赛中的表现，以调查VAR监测是否会像霍桑效应一样影响比赛表现。
样本包括2014 - 2017赛季未应用VAR的比赛（n = 1920）以及2018 - 2021赛季未进行干预的VAR比赛（n = 528）。使用广义线性混合模型来检验不同组中的不同变量。
研究发现，在比赛中实施VAR后，不干预的比例为32%。尽管未应用VAR，但它对进球（p < 0.01，科恩d值 = 0.04）、点球（p < 0.001，科恩d值 = 0.07）、任意球（p < 0.001，科恩d值 = 0.18）、抢断（p < 0.001，科恩d值 = 0.13）、犯规（p < 0.01，科恩d值 = 0.11）和红牌（p < 0.001，科恩d值 = 0.04）有显著影响。不过，射门次数、传球次数、角球和黄牌数量没有显著差异（p > 0.05）。此外，所有显著变量的效应大小均显示为小效应。
在中超联赛中，VAR在比赛中频繁干预。VAR监测对运动表现也有可测量的、尽管较小的影响，尤其是对防守表现。此外，VAR监测遵循国际足联鼓励进攻的理念，同时也有利于减少犯规。
