The wins have (mostly) come against poor teams
Keep in mind the quality of the teams the Celtics have played. The win over the Heat in Miami was certainly a good one, but the other three have come against notably weaker competition.
The Celtics’ first win came against the Jazz, who were also 0-4 and have since gone on to lose four more. In what looked to be a blowout at halftime, the Jazz made the game competitive in the fourth quarter, outscoring the Celtics by 12 and cutting the deficiti to 6 with 4:28 to play.
In the second win, at Orlando, the Celtics blew another lead and the Magic almost tied it with a 3-pointer with four seconds to play, but Arron Afflalo was a step inside the 3-point line when his shot fell.
The fourth win was a solid one against Orlando at home, but the schedule gets tougher. Five of the Celtics’ next eight games are on the road and six of their next seven are against Portland, Minnesota, Houston, San Antonio, Indiana, and Atlanta.