If Kevin Garnett's knee does not allow him to be the hyperactive perpetual motion machine anchoring the Celtics' defense, Boston has no shot at defending its title. And until K.G. proves he can go 36-40 minutes a night, the Celtics are no better than the third best team in the Eastern Conference.

If, however, the reigning NBA Defensive Player of the Year has healed enough from his two separate second-half layoffs to recover his bounce, the Celtics are once again the team to beat.

After Garnett's knee gave way on Feb. 19, the Celtics lost that night's game to the Jazz and six of their next 13 as the Cavaliers pulled away in the race for the league's best record. Garnett returned briefly, playing between 15 and 18 minutes a night in three wins and a loss before shutting it down again.

Though Boston has no shot at catching Cleveland in the final week, the C's (59-19) are gamely holding off the Magic (58-20) for the second seed in the East. Boston has won five straight during Garnett's second convalescence with three different players leading the team in scoring and four different guys leading the team in rebounding.

With Garnett, the Celtics are the deepest team in the league. Without him, that depth is irrelevant.

Nine different Celtics have led the team in scoring this year. Season scoring leader Paul Pierce has led the Celtics in scoring only 37 times in 78 games. By comparison, LeBron James has led the Cavs in scoring in 62 of 78 games and Kobe Bryant has led the Lakers in 61 of 78 games. As the Celtics proved last year in dispatching LeBron and Kobe in the playoffs, the team with more legit scoring options when a superstar is forced to pass out of a double team often prevails.

The scariest part for potential Celtic playoff foes is that — when healthy — Boston is actually better than it was last year when it went 66-16 in the regular season.

Here are the top five reasons the Celtics are improved from the team that won it all last year.

Rajon Rondo

Rondo has spent the season showing everyone why Danny Ainge would not include him in the deals that brought Garnett and Ray Allen to Boston. He is a physical freak that presents nightmares at both ends of the court. His improvement is a major reason a healthy Celtic team would be tough to beat four times in a series.