This time last year, the roles were reversed. The Nets finished the 2020-21 regular season with the No. 2 seed, while the Boston Celtics defeated the Washington Wizards in the first game of the play-in tournament to secure the East’s No. 7 spot. The Nets, with a roster headlined by Kevin Durant, Kyrie Irving and James Harden, made quick work of an outmatched Celtics team. Brooklyn won the series, 4-1, only surrendering the first game on Boston’s home court. But things have changed since that fateful series. Boston’s mastermind, Brad Stevens, moved into a front office role and poached Nets’ lea…