This Rajon Rondo, in particular, is worth every red cent. And so now that the Celtics reportedly have rewarded Rondo with a five-year contract extension worth in the neighborhood of $55 million, it is incumbent upon Rondo to continue earning his money.

The Celtics will not be the only ones far better off for it.

Rondo will be, too.

The Celtics are a perfect 4-0 today following yesterday’s 97-87 win over Chris Paul and the New Orleans Hornets, and a funny thing has happened as the Celts look to fulfill Rasheed Wallace’s preseason prediction of 72 victories: Rondo has been perhaps their best player. While Celtics coach Doc Rivers was praising captain Paul Pierce after his team’s latest victory -- "He’s been absolutely amazing," Rivers told reporters -- Pierce was transferring the praise to Rondo.

"I think he’s just mature," Pierce said in his postgame press conference. "He understands that he’s the quarterback out there, and he understands he has to do it with his defense and his distribution. He understands that we have so many weapons out there . . . I said to Rondo a couple of years ago, he should lead this league in assists with the weapons that we have out there. He’s doing a great job facilitating offense and being the quarterback. He understands that he doesn’t have to score. Last year, I think he scored a little bit more. I think that was due to a lot of the injuries we had and him just stepping up in that category. But what he’s been doing these four games into the season, his maturity has been tremendous to watch."

So has his performance.

As for the contract extension, it really was only a matter of time. If the Celtics didn’t sign Rondo before tonight’s midnight deadline -- funny how that 48-hour extension facilitated a deal, eh? -- they would have signed him in the spring, even if they had to match an offer. When you get right down to it, the final numbers were all that were to be determined. Rondo had no leverage to go anywhere, yet the Celtics paid him essentially what he asked for from the start. The Celtics and agent Bill Duffy played negotiating games from the moment Danny Ainge went public with criticism of Rondo last summer, following a postseason during which Rondo almost averaged a triple double.

These Celtics are far healthier and far more talented than the Celtics of last spring, and let the record show that Rondo has tailored his game to match. So far this season, Rondo has taken 23 shots in four games -- during last spring’s first-round series against the Bulls, he twice took more than 20 shots in a single game -- and piled up more assists (47) than any player in the league. Only Steve Nash has more assists per game (42 in three games, an average of 14.0). Rondo has the best assist-to-turnover ratio of any starting point guard in basketball at the moment (5.22 to 1). For every turnover he has committed (nine), he has taken more than his share back (10 steals).

Ultimately, isn’t that all what a point guard is supposed to do? Run the offense and set up the scorers. Protect the ball. Play good defense. Score when necessary, which is almost never at this particular point in time. For the new-and-improved Celtics, Rondo has options the way the Tom Brady of 2007 had receivers, from Paul Pierce and Ray Allen to Kevin Garnett, Rasheed Wallace and even Marquis Daniels.

On Friday during the Celtics' 118-90 dismantling of the Chicago Bulls at the TD Garden, Rondo took two shots. Two. He finished with 16 assists, turning the kind of pure point guard performance that would have made John Stockton beam. He also grabbed eight rebounds.

With regard to Rondo’s development, we all understand the issues here. At times during last postseason, Rondo looked more interested in collecting triple-doubles than he did in winning games. Despite his generally stellar play, he made some bad decisions and took some ill-advised shots. So far this year, those mistakes have been weeded out. The result has been a Rondo who has been playing like one of the truly elite point guards in the league, a fitting development given that Rondo and the Celtics now have agreed on a contract that will make him one of the cornerstones of the franchise for years to come.

Today, both sides are getting exactly what they wanted.