WALTHAM — At the beginning of the season, the Celtics weren’t sure if they could win.
“The first couple of games, it was 50-50,” Gerald Wallace said after practice on Saturday.
Too much was new, unfamiliar — players, coach, scheme. They were also surrounded by talk of “rebuilding” and “tanking,” and left to fill the holes of departed stars, and their best player still recovering from injury.
But 21 games into the season, much has changed.
The Celtics have won five of seven to improve to 9-12, and sit atop the Atlantic Division heading into their game Sunday against the 5-13 Knicks in New York. Full story for BostonGlobe.com subscribers.