C's in for a bittersweet reunion

Dallas Mavericks coach Rick Carlisle did his due diligence when he investigated trading for Celtics point guard Rajon Rondo by gathering impressions from Doc Rivers, Danny Ainge, Brad Stevens and former teammates.

Most of the feedback was positive; the stray negatives were quickly put into context.

"If there's one thing I've learned in my 31st year of NBA basketball,'' Carlisle said, "you can't take hearsay about people and make that an obstacle.

"You have to experience people for yourself.''

Predictably, Carlisle's initial exposure to Rondo has been enlightening. When Rondo is at his best (and he's had some moments already in Dallas), he's engaged and electric. When he defends with the same passion as he distributes, he can be a game-changer.

"Contrary to what a lot of people say about him,'' Carlisle said, "he's thirsty for knowledge. He's a sponge; he wants to learn as much as possible about our team.''

Rondo returns to the Garden on Friday night with Dirk Nowitzki, Monta Ellis and Chandler Parsons in tow, offensive weapons that only enhance his exceptional court awareness. They are weapons he simply did not have in a Celtics uniform this season.

The sample of numbers are obviously small (six games), but according to NBA advanced stats, Rondo's addition to the Dallas lineup has accomplished just what you would have thought: The Mavs are better defensively with Rondo, but their numbers have dipped offensively.

In 28 games without Rondo, Dallas' offensive rating was 113.6. With him, it is 106.3. With Jameer Nelson (a notoriously poor defender) at the point, the Mavs had a defensive rating of 105.1. That has dropped to 100.6 with Rondo in the lineup.

Where Rondo has really shined has been guarding the 3-point line. Players are shooting 14.2 percentage points below their 3-point averages against Rondo in a Mavericks uniform. Yet once they get inside that 3-point line, opponents are shooting 11.6 percentage points above their average. Overall, in the six games Rondo has played with Dallas, opponents are shooting 51.6 percent against him.

In other words, so far, the numbers aren't that much different from when he was in Boston. In 22 games with the Celtics, opponents shot 50.3 percent against him.

Be prepared to witness a rejuvenated Rondo who will assail his former team with increased intensity and energy. He's playing for a contender, a contract and, in some respects, his reputation.

"This second half of the year is a very big one for Rajon,'' Ainge agreed. "Dallas is getting a player who is very motivated to prove he's a max guy.''

Rondo should be greeted with a rousing ovation from a grateful Boston crowd, which had a front-row seat to one of the most unique talents in the game. He's earned their gratitude and has the championship ring to prove it.

And yet, you can't help but watch footage of Rondo ruthlessly and relentlessly tracking OKC star Russell Westbrook from end line to end line Sunday in a Dallas win (he helped hold his nemesis to 5-of-23 shooting with five turnovers) and wonder, Why didn't he play like that in Boston?

That inspired defense was absent in his final months in a Celtics uniform. In fact, while there were some prodigious spurts of on-the-ball defense during his Boston career, Rondo didn't accomplish it consistently enough to merit elite status. Whether that pattern will continue in Dallas remains to be seen.

"I didn't study or analyze that part of his game,'' Carlisle said, "but the reality is, when you come over to the Western Conference in this day and age at the point guard position, you are in for a war every night.

"The guy you are lining up against has something in his toolbox that he's phenomenally great at, and you better be ready to battle.''

The reason Rondo didn't sustain that kind of effort in Boston is simple: human nature. When you are winning and contending, it's easy to get up for every game. When you are losing and slipping into that dreaded wasteland known as irrelevancy, which is where the Celtics are mired as they rebuild, it takes a special person with exceptional resolve to maintain his ferocity.

As Mavericks owner Mark Cuban explained to Eddie Sefko of The Dallas Morning News when addressing Rondo's renewed approach, "If you've ever been in a company that's failing, you know the effort isn't the same.''

Obviously this won't warm the hearts of impatient Celtics fans who can't understand why the key player the team acquired, Brandan Wright hasn't found a permanent place in the rotation since he arrived. The trade exception was the true haul in the deal. There's reason to believe Jae Crowder has a bright future, but the sentiment lingers that the Celtics should have gotten more, and might have if they'd waited.

"Waiting isn't the answer,'' Ainge retorted. "Teams who are in the running are far less reluctant to make major changes in late February.''

The pool of compatible teams was shockingly small. It had to be a contending club with deep pockets (to entice Rondo to stay after this season) that needed a point guard. Sacramento wasn't ever really in it because Rondo balked at staying long term. New York had nothing to offer, and the Lakers didn't bother because they hope to pry him free once free agency starts in July. That left Dallas and Houston.

At his introductory news conference, Rondo said: "I've been fortunate enough to play for future Hall of Famers and great teams and a great coach in Doc Rivers. And to get back to that situation and be able to play with future Hall of Famers and a great coach and a team that's ready to contend for a title, I'm fired up.''

We can only wonder how Brad Stevens and the non-Hall of Fame teammates he left behind feel about that.

By most accounts, Rondo and Stevens had a decent relationship. Last summer, the coach put his star point guard through individual workouts and spent considerable hours working with him on refining a jump shot that has long been identified as the Achilles' heel of his repertoire.

Rondo wanted to buy in, but he succumbed to the inevitable tedium of losing. Stevens deserved better, but he's a big boy with thick skin. He must be, or he never would have signed on for this long-term reconstruction that must be stripping years off his youthful visage, the way it does in those before-and-after shots of presidents.

Credibility comes to players and coaches alike in only one way: by winning. Until Stevens does it on the NBA level, the doubts will linger, just as they did for Chuck Daly before he morphed into the Detroit Pistons whisperer who pushed all the right buttons of a championship team brimming with difficult personalities. Prior to that, Daly was a 51-year-old out-of-work coach who had gone 9-32 with the Cleveland Cavaliers.

Before he was the keeper of Ubuntu, Doc Rivers was a bad-luck coach in Orlando whose stars couldn't stay healthy. He was teetering on the brink of a firing during his early years in Boston before the New Big Three came along and joined forces with him to win it all.

Rondo wants another ring and decided to move on. Who can blame him? Rivers, the coach he butted heads with so frequently, made the same decision.

Now it's only Ainge who is left from the 2008 championship core.

"I'll miss Rajon,'' Ainge said. "My job was easier than coaching him. I didn't deal so much with the ups and downs. When he sat down with me in my office, I got the Rondo who was listening, the humble Rajon who wanted to get better. I loved my time with him.''

Marcus Smart has been anointed the future point guard for Boston, but that is mildly problematic at the moment. He isn't ready to be Rondo, now or ever. Their skill sets are vastly different, and Smart isn't yet equipped to become the face of the franchise, which is why his starts and his minutes will be monitored and expectations will be tempered.

"Marcus does everything you want defensively,'' Ainge raved. "His [defensive] instincts are ridiculous. He has a ways to go offensively.''

It will be bittersweet Friday for Ainge and the Celtics to watch Rondo fill the box score for someone else, especially considering the lingering feeling among some coaches that he could have and should have done more in Boston in his final days.

Fans are more emotional. They just know the Celtics stink without Rondo.

This is hardly a news flash, but they weren't all that good with him either.