One big vote for Marbury

Welcome to Boston, Stephon Marbury. You’re arriving just in time. The Celtics soon will be gearing up for another run at a world championship, and the simple truth is that they probably cannot win the title without you.

As for those skeptics who fear that Marbury may disrupt the chemistry the Celtics have built over the last 18 months or so, we ask:

Do you want to win another title or not?

After months of speculation (and more) that Marbury would end up with the Celtics, the talented and controversial point guard drove to Boston last night and is expected to sign with the team before tonight’s game with the Indiana Pacers. And over the next 2-4 months, depending on how far the Celtics go, we will learn just how much the Celtics needed him.

"You don't know how good it feels to know that it's just one thing, to have fun,’’ Marbury told the Globe’s Marc Spears by phone last night. "[Kevin Garnett] was like, 'Basketball is going to be fun again, kid.' Man, I can't wait. I'm so excited. I haven't slept in like three days."

Before we go on, let’s ask one question:

If KG is pumping him up, shouldn’t that be good enough?

Let’s be honest here, folks. Two months ago, when the Celtics were rumbling to a 27-2 start, they remained the class of the NBA. Since that time, they’ve gone 19-11, lost twice to the Los Angeles Lakers (including once in Boston) and been positively throttled by the much-improved Cleveland Cavaliers at Quicken Loans Arena. The Celtics suddenly seem to have an alarmingly short bench, with or without mighty Mikki Moore.

So Marbury comes with the reputation of being, you know, disruptive. So what. Over the years, the same was said of Dennis Johnson, Corey Dillon and Randy Moss, among others. Johnson and Dillon helped bring championships to Boston, and Moss shredded the NFL record book during his one full season with Tom Brady and helped the Patriots to an 18-0 record before the unfortunate, gut-wrenching events in the final minutes of Super Bowl XLII.

Even then, Moss caught the touchdown pass that gave the Patriots the lead and brought them oh so close to the only 19-0 season in NFL history.

Already, Marbury is saying the right things. In the Q&A with Spears, he said he will play as many (or as few) minutes as the Celtics want. His objective is to win. Marbury’s reputation for being selfish may be well-earned, but he has never had an opportunity quite like this one, either. If Marbury doesn’t live up to his word now, his credibility in the league forever will be destroyed and his reputation will be permanently damaged.

This? This is an opportunity for Marbury to rehabilitate his image. It’s a chance for him to validate much of his career. And because the Celtics will be paying Marbury only a prorated share of the veteran minimum of $1.3 million -- between $350,000 and $400,000, though that number essentially doubles because of the luxury tax implications -- the Celtics can cut bait with Marbury at any time without taking a major financial hit.

Understand?

Marbury has more invested in this than the Celtics do.

He needs them as much (or more) than they need him.

If anyone out there is continuing to operate under the delusion that this Celtics team is as capable as last year’s with regard to winning the world title, take a closer look. The Celtics team that won the championship last June had James Posey, Sam Cassell and P.J. Brown on the bench. They ran nine or 10 deep. Cassell, Brown, Posey and Eddie House all made notable contributions last postseason, and the last member of that group now should be freed up to do what he does best -- shoot -- with Marbury assuming control of the ball.

Last season, lest anyone forget, Cassell came with questions. Many wondered whether Cassell would be capable of accepting a lesser role behind Rajon Rondo. Few remember that Cassell scored an important 13 points in Game 5 of the Atlanta series and another 13 in Game 1 of the Cleveland series.

All the while, with the no-nonsense Garnett setting the tone in the locker room and on the court, Cassell so seamlessly fit into the Celtics fabric that the club brought him back for another season based purely on his presence. What Cassell didn’t have anymore was the game to help this team at this time.

Unlike Cassell, what Marbury lacks at this point is the championship pedigree. At the same time, he has the game to help this Celtics club. At the moment, minus Posey, the Celtics don’t have the best defense in the NBA anymore. At the moment, they don’t have home court advantage for the playoffs, either. Last season, each of those assets played a significant role in delivering a 17th NBA championship to Boston, and there are currently teams with more championship incentive than the Celtics holding leverage in key areas.

The Cavaliers have the best defense and the best home record. The Lakers have the best record on the road. In all likelihood, the Celtics will have to beat at least one of those clubs -- and, more likely, both -- on the way to an 18th world title, and the chances of that happening without Marbury seem to be dwindling by the day.

In sports, there are no absolutes. The best team doesn’t always win. Given their careers and the events of last year, nobody understands the necessities of winning more than Garnett, Ray Allen, Paul Pierce, Danny Ainge and Doc Rivers. More than anyone, as a former teammate of Marbury, Garnett knows what Marbury could bring and what he could subtract. Rest assured that the Celtics long ago decided to make this investment, largely because they know the two most important rules when it comes to defending a championship.

As difficult as it can be to reach the top, it is more difficult to stay there.

And if you’re not getting better, you’re getting worse.