This study investigates the impact of restricted crowds caused by the COVID-19 pandemic on the margin of victory of games in the NBA. Using 12,500 game-level observations from 11 NBA seasons from 2010/11 to 2020/21, the study first shows that during the COVID-19 season of 2020/21, games had a greater average margin of victory than any of the prior seasons. Regression results reveal that games played in front of restricted crowds were more likely to be won by a margin of 15, 20, or 25 points than games played in front of non-restricted crowds. The results indicate similar effects for games played in an empty arena or in front of a small crowd. Implications for the NBA and other major team sports leagues are discussed.