Comparing the home advantage in regulation and overtime in the National Basketball Association


The home advantage reflects the finding that the home team wins over 50% of the games played under a balanced home and away schedule (Courneya & Carron, 1992).  Although teams competing in their home venue are more likely to win, Jones (2007) found the advantage diminishes throughout the game and into overtime in the National Basketball Association (NBA). Jones’ examination, however, was restricted to two seasons encompassing only 157 overtime games whereas typical home advantage studies examine several seasons’ worth of results to determine trends. Thus, the purpose of this project was to examine potential differences in the home advantage for games completed in regulation time versus those decided by overtime using a larger sample consisting of 12 NBA seasons. Home winning percentages for both regulation time and overtime games were obtained for 32 teams. A paired sample t-test was executed to compare winning percentages of regulation time (14,429) and overtime (906) games for each team in the NBA over 12 seasons. The results demonstrated that there was a significant decrease in winning percentage for the home team from regulation time (M = 60%, SD = .08) to overtime (M = 56%, SD = .12); t(31) = 2.20, p = .03, r = .238. As explained by Carron, Loughead, and Bray (2005), the home advantage is dependent on a variety of factors including the crowd, learning, travel, and rules, which then affect psychological and physiological states, critical behavioural states, and performance outcomes. Discussion is centered around salient explanations for the observed decrease in winning percentage in overtime.