NBA personnel matters have returned to the realm of rationality this week. No, the Knicks did not fire team president and coach Isiah Thomas and reassign chairman James Dolan — but good moves occurred just down the road in Philadelphia, as the 76ers jettisoned longtime general manager Billy King and replaced him with the Nets’ GM, Ed Stefanski. Also included in the category of reason is Cleveland’s resolution of Anderson Varejao’s holdout with a sensible, short-term, inexpensive contract.

In a league where executives such as Thomas and Minnesota’s Kevin McHale are allowed to blunder over and over again, leaving their teams in the dumps and their fan-bases equally embarrassed, aggrieved, and exasperated, King’s transgressions in Philadelphia seem fairly minor. Yes, he is the GM who traded Allen Iverson — but he did so only after it was apparent that the team would be unable to build a winner around him. King’s other big failure was in overpaying for marginal players such as guards Kyle Korver and Willie Green, and center Samuel Dalembert.

That might not seem like enough to get someone fired, but the Sixers are approaching a critical juncture in their rebuilding phase. This summer, when the bloated contracts of Aaron McKie (a King signing) and Chris Webber (a King acquisition) come off the books, the Sixers will have the rarest of commodities in the NBA: cap room. The team will be approximately $16 million under the cap with an attractive class of free agents entering the market. If evaluating and signing veteran talent has been one of King’s weaknesses, then it was high time to make a change.

The timing of the change is also a signal that the Sixers understand that they have more assets looming than just cap room. Point guard Andre Miller’s contract expires after next season, and his replacement, Louis Williams, a third-year player taken by the Sixers in the second round of the 2005 draft, looks ready to step up and take the reins of the offense. Shrewd work at the trade deadline in February could make the Sixers’ situation even more attractive.

Stefanski’s first task is to build a nucleus, and he inherits a good personnel situation from his predecessor. The Sixers have one cornerstone in swingman Andre Iguodala, a rising star who took over as the team’s primary option on offense after the Iverson deal last December. Dalembert, despite his marginal status, may be slowly emerging as another cornerstone. The lanky 26-year-old was given a contract well out of proportion to his demonstrated talent a couple of years ago, but the former Seton Hall pivotman has made steady progress with his game, and while it’s hard to forecast any All-Star games for him, his play suggests that he will be a solid defensive force in the middle for some time. First-round draft pick Thaddeus Young has played very well in limited action so far this season; this bodes very well for the future.

The supporting cast is also about halfway there. Korver is the long-range marksman off the bench, Reggie Evans provides rebounding muscle, and the rest are either works in progress or in bad contracts, such as Green. With the Nets, Stefanski played an integral role in engineering two of the Nets’ most important deals, the draft night trade that brought Richard Jefferson into the fold in 2001, and the 2004 deal that brought Vince Carter from Toronto. With the Sixers, he’ll need to find a true power forward to add rebounding muscle and inside scoring, and he’ll need to fill out the periphery of the rotation, either by sorting through some of the team’s younger players such as Rodney Carney, Shavlik Randolph, and Jason Smith, or by hiring some of the Development League stars.

It’s usually standard operating procedure for the incumbent head coach to start packing up his office when a new GM takes over, but Stefanski might want to think about keeping the current coach of the Sixers, Maurice Cheeks. Although Cheeks hasn’t had much to work with in his two full years on the Sixers’ bench, he’s guided them to 38 and 35 wins, respectively. Although this season’s record isn’t pretty (5–12 going into last night’s game against Boston), the team’s point differential suggests that it is nearly two wins better than that. And here’s the biggest indicator: The Sixers are playing very good defense. Going into last night’s action, they were seventh in the league in Defensive Efficiency (points per 100 possessions), a sure sign that Cheeks has his motley crew playing hard. They rank only 24th in Offensive Efficiency, but with the talent infusion ahead via free agency, a lottery pick, and what they receive in return for Miller, the Sixers figure to improve on that mark quickly.

Sixers’ ownership thought outside the box in making a change in the executive suite. If Stefanski applies comparable creativity to a promising situation, the Sixers will quickly pass the locals and return to their role as a force in the Eastern Conference.

mjohnson@nysun.com