“I know this may be hard to believe,” Smart said, “but I was even more confident in those first two months just for the simple fact because I knew everything was new.” He applauded the Celtics for sticking to their lineups with him as the starting point guard, and he has rewarded them. Smart averaged 12.1 points during the regular season. His .418 shooting percentage was the second best of his career, and he set a career mark with 5.9 assists per game. In the postseason, when healthy enough to be on the court, he’s been brilliant offensively, scoring 15.7 points with 6.1 assists and shooting .345 from 3-point range. That’s an extra 3-pointer a game from what he gave Boston during the regular season.