Detroit ? Rasheed Wallace is leaving Detroit, which makes this a sad week for the local linguists. No more ‘Sheedish in Detroit. No more Rasheed mocking “them bandwagon-(bleep) cats” or saying of the refs “some of them cats are felonious, man.”

Wallace is going off to Boston to win another ‘ship. That’s ‘Sheedish for championship, in case you’re not fluent.

Wallace arrived at the 2004 trade deadline with one of the worst reputations in all of sports. He was considered the loosest of cannons, an overpaid player who had the talent to be a star but lacked the drive.

He won a championship with the Pistons and nearly won another. Many fans love him, although he always had more detractors than any of his teammates.

Bringing Rasheed Wallace to Detroit was absolutely the correct decision.

So is letting him leave.

Wallace was right for the 2004 Pistons. He would be wrong for the 2010 Pistons. And this is not really about his skills, which are diminished but still valuable. It is about his attitude.

Wallace is a man of many contradictions, and maybe the biggest is this: He prefers to blend in on the court but has a dominant personality off it. For the last five years, he has been the funniest Piston, the loosest, the one who played the loudest music and had the most obvious disagreements with coaches.

In an odd way, he has been a leader–and not always in the right direction.

Wallace’s personality fit with the Pistons of Chauncey Billups and Ben Wallace. Those two were established stars who already had played in the conference finals. That team needed a piece to push it into true championship contention, and Rasheed — with his outsized talent and varied skills — was the right piece.

But he would be the wrong piece for a young, retooling team. He was never known for his work ethic. (I once asked him how much he works on his game in the summer. Kobe Bryant, for example, says he makes 1,000 jump shots a day in the summer–not takes, makes. Rasheed told me he prefers to rest his body.) And Wallace sometimes gets bored and coasts through regular-season games.

You don’t want that rubbing off on, say, Charlie Villanueva. The Pistons would much prefer to re-sign Antonio McDyess for similar money if they can. If anything, McDyess cares too much. He is a model pro. If Villanueva copies everything McDyess does for the next two years, he could be an All-Star.

Wallace was always a controversial player. But in his first two or three years with the Pistons, his biggest controversies were ill-timed technical fouls and playoff guarantees. In the last two or three years, Wallace became increasingly frustrated with coaches.

It is not surprising to see him leave for a reserve role in Boston. This is another Rasheed contradiction: He has a large basketball ego, but it is not tied to scoring. It is tied to winning.

He probably could have gone to Charlotte and started for his old coach Larry Brown. He would have put up better numbers there.

But I can’t see Rasheed losing 50 games a year at this stage of his career. He would find it humiliating.

Wallace might just win his second championship next year. He fits with the Celtics in the way he used to fit with the Pistons — but never would again.