But it wasn’t just New York where the Covid restrictions that have governed life in sports facilities changed dramatically this week. The Utah Jazz had more than 13,000 fans in uniform white shirts at their game on Sunday night, while nearly 12,000 fans watched the Phoenix Suns beat LeBron James and the Los Angeles Lakers. When is an arena half-full and not half-empty? When it’s in Philadelphia and 76ers star Joel Embiid is begging the crowd for more noise. “It felt like 30,000,” Sixers coach Doc Rivers said of the crowd of roughly 11,000. The atmosphere at NBA playoff games will only get rowdier as the postseason goes on. The Miami Heat, Atlanta Hawks and Dallas Mavericks announced plans for near-full arenas at their games later this week, and Kyrie Irving will make his return to Boston in front of a crowd that has been waiting for two years to give the ex-Celtics star his performance review. And this is only the first round. As vaccination rates tick higher and the nation’s Covid rates plunge, it seems almost certain that the NBA Finals will be electric and played in front of packed arenas by the middle of July.