Analyzing the impact of the home-away effect on game outcomes: evidence from the Chinese Basketball Association Analyzing the impact of the home-away effect on game outcomes

Sample: This study investigates the impact of the home-and-away effect on the 2022-2023 season of the Chinese Basketball Association (CBA), which is due to the fact that COVID-19 employs a hybrid tournament system combined with a home-and-away system. Method: Using a mixed effects model, this study analysed 413 matches from that season and found differences in the impact of the home and away effect across different formats. The home and away effect is then quantified by comparing the difference between home and away indicators under a home and away system. Result: The home-away effect is more pronounced in home-and-away games, with home teams enjoying statistically significant advantages in key performance indicators such as the 2 field goal Made, 3 field goal Made, offensive rebound, defensive rebound, and turnover, which translated to a higher win rate and point difference. And the home and away effect is greatly diminished under the tournament system. Conclusion: The study confirmed that indicators such as three-point attempts, steals, and turnovers have a significant impact on the outcome of the game under the influence of the home-and-away effect, and visually quantified the home-and-away effect through percentage value-added. The main causes of the home-away effect, such as crowd noise and court familiarity, were also explored, and the role of referee bias was also mentioned. Certain strategies and suggestions are provided for coaches ‘decision-making and players’ training matches.