Celtics: 53 wins
The Celtics won 39 games in an abbreviated season last year, and they haven't won fewer than 50 games in a season since their championship season of 2007-8. Ray Allen is gone, but expectations are as high as they've been during the Big 3 era. Injuries could derail them, but barring that, it seems likely the Celtics will challenge for the East's 2d-best record.
Prediction: Under