NEW YORK — Celtics  coach Doc Rivers  took full responsibility for the historic futility of his offense has suffered through in dropping the first two games of their series at Madison Square Garden.
For the second straight game, the Celtics established a playoff franchise record for fewest points in a half when they scored just 23 in the second half of Tuesday’s 87-71 loss to the Knicks.
“We are who we are,” Rivers said when asked about the effect of not having Rajon Rondo  available. “We can’t apologize for that. That is who we have been left with and I think it is good enough to win. So far, I haven’t gotten them to the right spots. We can play better and we have to play better.”
The Celtics led 48-42 at the half. But Iman Shumpert hit a pair of threes early in the third quarter, part of a 29-6 New York run that put the Knicks in complete control. The Celtics were outscored 32-11 and converted just 4-of-17 shots from the floor in posting another abysmal third-quarter performance.
“They attacked us,” Rivers said. “We didn’t handle it very well. We have to be able to do better. I don’t know what we are doing wrong in the beginning of third quarters but we gave up those two back-to-back threes, which helped their confidence. It was a tale of two halves.”
Paul Pierce  led the way with 18 points but came out with four minutes left as the Celtics conceded.
“He needs some help,” Rivers said. “I think Paul was playing pretty well. He started getting tired in the second half because he tried to do everything.”