Better late than never.

With the season on life support and Jason Kidd contemplating life in places such as Cleveland and Dallas, the Nets finally made the move for which fans have long clamored: changing the frontcourt. Out go the laughably unproductive Jason Collins and Malik Allen, and in come youngsters Sean Williams and Josh Boone. Game 1 of the experiment came last night against Sacramento.

“This isn’t a panic move,” coach Lawrence Frank said yesterday, and truer words have never been spoken. In fact, this was the opposite of a panic move. This was a move that was so long overdue — by three weeks in the case of Allen, and about three years in that of Collins — that Nets fans had practically given up hope that it would ever happen.

That’s Frank’s biggest weakness as a coach: He loves big guys who don’t screw up, regardless of how shockingly unproductive they are. That’s why Clifford Robinson hung around so long, and that’s why players such as Allen and Collins have stayed in the lineup despite their inability to score, rebound, draw fouls, or block shots.

To Frank’s credit, he finally made the change. Many coaches, one of whom works across the river from Frank, are so stubborn that they ride their system right down the tubes. But by process of elimination, he finally succumbed to the logic that it had to be his frontcourt — because it wasn’t Kidd, or Richard Jefferson, or Vince Carter that was causing the Nets to fall behind by double figures in the first half every night.

While we’re discussing Frank, by the way, this one flaw doesn’t mean the Nets should cut him loose — far from it. People always the right call; in the case of the current frontcourt, he clearly did not. With Collins and Allen, the issue wasn’t that they avoided negative plays, but rather that they never made any plays. This was quite possibly the least productive starting frontcourt pairing in NBA history. On the season, the Collins-Allen duo averages 6.1 points and 5.5 rebounds per game. Ready for the punch line? Those are their combined stats.

Using my Player Efficiency Rating (PER, a per-minute rating of a player’s statistical effectiveness), Collins was the single least effective regular player in basketball this season. That shouldn’t come as a shock, though: He was last year, too.

To give you a picture of Collins’s awfulness, the league average in PER is set at 15.0, and usually only scrubs or defensive specialists fall below 10.0. Collins’s rating? 0.9. He hasn’t had a rating in double figures since 2003–04, and hasn’t even come close in any of the past three seasons.

Yes, he’s a good defender and he sets nice screens, but good heavens, is it really possible for an NBA player to do this little? It’s not just the invisible scoring: He also doesn’t rebound. His average of 5.3 boards per 40 minutes is worse than that of several point guards.

Not that Frank had many other options. Unbelievably, three of the league’s four worst PERs belong to the Nets’ frontcourt players. Jamaal Magloire, at 2.21, was third from the bottom (I guess $4 million doesn’t buy what it used to). And the hobbled Nenad Krstic, at 2.23, was fourth, though at least he has an excuse.

Compared to those guys, Allen’s 8.73 rating — merely the 27thworst of the league’s 300 players with enough minutes to qualify — must seem like a godsend. But in any other sphere of reality, his performance would be considered severely lacking. Allen’s scoring, shooting percentage, rebound, and turnover rates all are well below par for an NBA big man, and his defense isn’t exactly world-class either. That’s why the 29-year-old journeyman was available for the veteran’s minimum in the first place.

And that, consequently, is why the Nets entered yesterday’s game ranked 26th out of the league’s 30 teams in Offensive Efficiency (my rating of a team’s points per possession). With such miserable output up front, it’s a miracle they weren’t 30th.

Contrast the Allen-Collins tandem’s production with what Boone and Williams have done, and Frank’s move becomes slap-in-the-forehead, what-the-hell-took-you-so-long obvious. Boone is the team’s best rebounder, and he’s a veritable scoring machine compared to Collins. While his 24.1% free throw mark is just a wee bit troubling (we’ve seen Hack-a-Boone each of the past two games), his activity at both ends should make up for it. Williams’s numbers have been so good that Nets observers have been left puzzled why it took this long to get him out there: In virtually every category, he easily outranks the other frontcourt players.

With the new frontcourt yesterday, the Nets managed to avoid their typical early deficit. In fact, Boone and Williams combined for 10 points in the first quarter — a feat that would take nearly two games for Collins and Allen — as New Jersey took an early lead, for once. Williams also blocked six shots in the first half. By comparison, Collins has four the entire season — and the two combined to shoot 5-for-9 from the floor.

Yes, it was a home game against a bad team, so don’t consider the season saved or make any other grand proclamations just yet. What we can say, though, is that the Nets finally made the one move available to them that maybe, just maybe, could finally get this season turned around. As frustrating as it was to watch Frank delay the inevitable for so long, it’s easy to lose sight of the fact that the Nets still have 57 games left to help this cause. After last night’s move, it’s far easier to contemplate such an event actually happening.

jhollinger@nysun.com