Celtics faltering on the defensive end of the floor

NEW YORK -- The Boston Celtics aren't quite backing into the playoffs like whoever ends up with the eighth seed in the Eastern Conference. It's more of a sideways shuffle.

The Celtics followed Sunday's big win over the Cavs with a confounding loss in New York on Tuesday. After starting the season 23-5, Boston has barely been a .500 team, going 25-24 since Christmas. Most disturbing is that their defense, which has been their backbone for the last three seasons, has never been worse.

The Celtics have allowed their opponents to score 114.4 points per 100 possessions over the last four games. Only once in the last three seasons have they been worse defensively over a four-game stretch, and that was last March, when Kevin Garnett was out with a knee injury.

The Celtics have shot 52 percent or better in three of the four games, and yet they've lost all three.

"Usually, those are guaranteed wins," head coach Doc Rivers said Tuesday. "Right now, they're not. I really think it's as simple as a lack of focus. And it's on the defensive end right now."

The Celtics are healthy, or at least as healthy as they've been all season. But as inconsistent as they've been since Christmas, defense hasn't really been the problem until recently.

Garnett's mobility has looked suspect and they're not on the same level that they were when they won the NBA title two years ago, but the Celtics have still been at the top of the league defensively.

At the All-Star break, the Celtics had the No. 1 defense in the league, allowing just 99.0 points per 100 possessions. At that point, their issues were on the offensive end of the floor, where they ranked 14th, even though they were the third best shooting team in the league. Turnovers were killing them and a lack of offensive rebounds wasn't helping either.

They were very efficient when they shot the ball, but they just weren't getting enough shots. In fact, they ranked last in the league in shot attempts per possession.

Turnovers have been a problem for the Celtics for each of the last three seasons too. In both 2007-08 and 2008-09, they committed the second most turnovers in the league per possession. They were in the same exact position at the break this season, so Rivers made it a point of emphasis.

"Since the All-Star break, we've had a complete focus on taking care of the basketball," he said. "And since the All-Star break, we've been pretty good at it."

The Celtics are committing almost two fewer turnovers per 100 possessions since the break, down from 16.7 to 14.8. Their offensive rebounding is still bad, but they're getting a couple of more shots per game.

That's why the defensive issues of the last week are so disappointing. The Celtics have improved on one end of the floor, but regressed on the other. A suffocating defense has been their calling card for the last three years, and now they're losing their identity.

"Teams definitely aren't intimidated by us," Paul Pierce said. "They come at us, and we've got to understand that. We're not a team that's going to walk on the court and teams back down from us."

In the last 10 days, the Celtics have allowed Manu Ginobili to score 28 points, Kevin Durant to score 37, Aaron Brooks to score 30 and Danilo Gallinari to score a career-high 31. With that in mind, they face the possibility of trying to stop Dwyane Wade in the first round of the playoffs.

Before Tuesday's game in New York, Rivers implied that winning games wasn't the biggest priority in the last nine days of the season, even though his team was just a game behind the Hawks for the third seed in the East. And it's possible that some of his starters will sit out one the final five games.

"We just want to keep a rhythm going in," Rivers said. "We want to win as many of these games as we can. But for us, it's timing, rhythm and health. That's the priority."

He may want to rethink things a bit. If the Celtics want to be an elite defensive team in the postseason, it would be nice if they can prove they can still dominate on that end beforehand. After Tuesday's game, Rivers kept referring to his team's lack of focus. And with the playoffs just 10 days away, the time to get focused is Wednesday night in Toronto.

"You just don't turn it on in the playoffs," Pierce said. "You've got to start building some momentum right now."

John Schuhmann is a staff writer for NBA.com. You can e-mail him here and follow him on twitter. The views on this page do not necessarily reflect the views of the NBA, its clubs or Turner Broadcasting.