The Nets stand just a game under .500 tonight after last night’s loss to Detroit, but don’t let that fool you. The win-loss record may say the Nets have been average, but in most respects, they’ve actually been horrible. Despite playing one of the league’s easiest schedules at the start, the Nets have the victory margin of a 4–13 team. If they continue to play this way, they’ll find themselves out of the playoff race quickly.

On the surface, nothing seems that different from a year ago. One thing in particular is notably better: the play of Richard Jefferson, who was plagued by ankle troubles a year ago, but was fifth in the league in scoring at 25.1 points per game entering last night’s game.

Beyond Jefferson, Vince Carter and Jason Kidd combine to give New Jersey one of the league’s best star trios. Carter has been off his game for the first month thanks to a thumb problem, but has shown signs of late of regaining his usual form. Kidd, for all his triple-double magic, has seen his overall production decline a bit, as he’s become such a reluctant scorer (averaged a very modest and career-low 12.8 points per 40 minutes), but this hardly explains why the Nets have played so poorly.

Many of the team’s problems are coming from its offense: The Nets entered Sunday’s game ranked 29th out of the league’s 30 teams in Offensive Efficiency, my measure of a team’s points scored per 100 possessions. That’s a despicable performance for a team that has a star trio at its core. Even with two of the team’s three stars not at peak efficiency thus far, they’ve still done more than enough to lead the Nets into the postseason with a quality supporting cast.

Ay, there’s the rub.

Beyond those three, the Nets have a shockingly weak support system. After the star trio, there are only two players who have been even mildly productive — as in, even productive enough to get into any other team’s rotation. The first is rookie center Sean Williams, who has performed beyond expectations after being selected with the 17th pick in the draft, but still battled the usual rookie demons of consistency and learning defensive concepts. The second is third-year pro Antoine Wright, who has cooled off considerably from his first-week offensive explosion, but is a solid defender who has become enough of an offensive threat that opponents must at least respect him.

That’s more than can be said of any of the other Nets — far, far more. Williams and Wright are flawed but moderately helpful. But the rest of the unit is downright comical.

You don’t believe me? Let me introduce you to the starting front-court. On our left, we have Malik Allen, who sat at the end of Chicago’s bench last year, but now starts for the Nets — primarily because the rules require five starters, and the Nets only have three. An alleged shooter, he’s hit 39.4% and averaging a paltry 7.0 rebounds per 40 minutes, managing to fall short of even the lowest of expectations.

Then there’s the center position, where the Nets have managed a feat I would have thought impossible: They have not one, but two players with a negative PER (Player Efficiency Rating, my per-minute rating of a player’s statistical effectiveness with the league average set at 15.0). The starter, Jason Collins, had the worst PER in the league a year ago at 3.02 — but apparently redoubled his efforts over the summer, because now he’s at -1.10. Though a quality defender, Collins is the worst offensive player in basketball. The worst. He scored one basket in his first nine games, for crying out loud, and is averaging only 1.7 points per 40 minutes for the year. While Collins is useful in small doses, especially against big post-up centers, there is only one team in the NBA he could start for.

Fortunately for Collins, he’s on it, because his backup, Jamaal Magloire, has been even worse, with a -2.00 PER. Magloire, who cost them only $4 million plus the services of Hassan Adams, has been an epic bust with an 18.5% shooting mark and disappointingly little activity at the defensive end. He hasn’t played in the past five games, and overall it’s hard to imagine a bigger flop thus far.

You want more? How about Bostjan Nachbar? After a strong season a year ago and a stellar preseason this fall, Bokie has gone completely in the tank. The 3-point specialist is hitting only 30.9% on triples and 37.4% overall, and seeing his minutes shrink in response.

How ’bout Josh Boone? He was supposed to take a step in his second year after giving solid numbers as a rookie. Instead, he seems intent on proving rumors that his questionable passion for the game is limiting his future improvement, and that his rookie year was a fluke.

And unfortunately, there’s also the case of Nenad Krstic. Many have focused on Carter, but in large part the Nets’ offensive predicament has been a result of Krstic’s slow recovery from last season’s knee surgery. Were the 7-foot Serb scoring in the high teens from the low blocks, the Nets might have been able to overcome the poor efforts from the other secondary players. Instead, he’s been as bad as any of them, shooting 32.9% with a marked decline in free-throw attempts and a Collins-esque 2.23 PER. New Jersey finally had to shut him down and give him a couple weeks away from the court.

With three stars, the potential returns of Krstic and Marcus Williams from injury, and the surprising play of Sean Williams, one can still imagine this Nets team doing some damage later in the season. But first, they have to arrive there with a foot in the playoff chase. While the Nets have been able to hang on by their fingernails through the first month, that’s not going to continue unless the secondary players stop leaving Jefferson, Kidd, and Carter to play 3-on-5 every night.

jhollinger@nysun.com