With 6 champs in 6 years, Celtics will try to end that trend

It was a few minutes after Denver's reign as NBA champion had come to an end last spring. The Minnesota Timberwolves were celebrating, their music and screams loud enough to be heard inside the room where Nuggets coach Michael Malone was somberly going through his final postgame news conference of the season. In that moment, it was official: Another season was going by without the NBA having a back-to-back champion, and Malone was left to state what has become obvious. "It is hard. It is hard. It is hard to repeat," Malone said. "It's hard to win." He's right. And there's never been an era in NBA history where it's been harder. Here are the last six NBA champions, in order: Toronto, the Los Angeles Lakers, Milwaukee, Golden State, Denver and now Boston. That's six different title-winning franchises in six seasons, a run of parity that the league has seen only once before — nearly a half-century ago. The days of dynasties may be on hold for now, replaced by a time when, for a variety of reasons, it's more difficult than usual to get to the NBA mountaintop and stay there. It's the Celtics' turn to try to buck that trend. "It's always hard to...