How have the Celtics so emphatically exceeded expectations this season? How has a team most expected to finish somewhere between sixth and 12th in a bad Eastern Conference become, inarguably, one of the NBA’s best through 57 games? One simple explanation: Outside of the small handful of rookies and 10-day contracts at the end of Boston’s bench, nearly every player on its roster is enjoying the best season of his career. A rundown, after the Celtics bludgeoned the Phoenix Suns 97-81 on Tuesday without Jaylen Brown to improve to 38-19 and strengthen their grip on second place in the East: — Brown, an NBA All-Star starter for the first time, is averaging 29.2 points, 7.0 rebounds and 4.9...
