With two-thirds of the season in the books, the top six seeds in the Western Conference are nearly set in stone. Dallas, Phoenix, San Antonio, Utah, and Houston are all playing .630 ball or better. They’re not just the five best teams in the West; they’re the five best in the NBA. Then the Lakers are secure, albeit adrift, in the sixth spot.

Aside from some jostling for position among the top five, the real drama will come at the bottom of the bracket. Seven teams are bunched within three and a half games of each other, and the fight for the remaining two playoff spots is just heating up.

Underscoring the competition (battle is too strong a word for a scrum among mediocre teams) is the draft class of 2007 that is said to be the deepest in years. Some teams should find it a better fate to earn good lottery position rather than get swept by one of the conference superpowers. With that thought in mind, let’s look at the contenders.

That Portland, 24–33, is in the hunt is indicative of how strange this race is. The Trail Blazers don’t seem to be trying to contend. They’re in year two of the post-Jail Blazer era and look to be getting some nice pieces in place. They still need a solid draft or two and time for youngsters already in the fold — like guards Brandon Roy and Sergio Rodriguez, and forwards Martell Webster and LaMarcus Aldridge — to develop into a nucleus before they can seriously think about the playoffs. Yet the race backed up to include them. If they get any closer, forward Zack Randolph may have to interrupt his Most Improved Player campaign with a sudden case of tendonitis or something.

At 24–31, Sacramento might seem equally out of place in the playoff discussion, but their point differential suggests they are somewhat better than their record indicates. Everyone is healthy too, which might indicate that this team is in for a run, but their schedule isn’t friendly. Seven of their remaining 27 games are against the conference elite and 14 are on the road. The Kings were widely considered a playoff team in preseason picks but now they’re a longshot.

Since Golden State, 26–31, hasn’t been to the playoffs in 13 years, even a couple of postseason losses to some behemoth would be welcomed like a trip to the finals. High-scoring guard Jason Richardson has just returned to the lineup, but the Warriors are miserable on the road, 6–21, and they embark on a long trip this week. The injury to point guard Baron Davis plus 14 road games and several more against the Texas teams, Phoenix, and Utah, should be enough to extend the Warriors’ streak of futility.

Most observers howled in derision when Minnesota, 26–30, dismissed coach Dwane Casey after the team split their first 40 games and replaced him with Randy Wittman who had coached Cleveland to a 62–102 record back in the pre-LeBron era. So far, Wittman’s track record is proving consistent. The TWolves are 6–10 under his watch. With a soft schedule ahead, Minnesota would be in great shape for a stretch run, but instead they look like a team that’s already peaked.

Three weeks ago, it looked like the Clippers, 27–30, had turned the corner; now, after losing seven of 10, it looks like they’ve fallen again. The Clippers were synonymous with the lottery until coming within one win of the Western Conference Finals last season. The problem is that they weren’t a young team then, and this year’s setback reflects a predictable decline from their aging guards, Cuttino Mobley and Sam Cassell, as well as a steep dropoff by center Chris Kaman. Point guard Shaun Livingston has improved but not to the superstar levels required to offset the plunging production from his teammates. A good draft is really just what the Clippers need, but organizational credibility may suffer if they fail to return to the playoffs. Last season will start to look like a fluke.

If the season ended today, Denver, 26–28, and New Orleans/Oklahoma City, 27–29, would be in the playoffs, and although both are surrounded by competition, several key signs suggest that they’re going to remain inside the playoff picture.

Both teams are as healthy as they’ve been all season. The Hornets still miss Peja Stojakovic, but with the return of point guard Chris Paul and forward David West, the Hornets have played very well, winning eight of their last 11. Assuming no other calamity occurs, Denver, though weakened by the absence of forward Kenyon Martin, is finally entering a stretch where they will have Allen Iverson and Carmelo Anthony on the floor together.

The Hornets have a difficult schedule ahead, but at the level they’ve played, it wouldn’t be a surprise to see them mount a challenge for the five spot if the Lakers malaise continues. Denver’s schedule is gentler, and they should be able to outscore most of their weaker opponents. However, if the injury bug that has settled over the Rockies continues, some team — my pick is the Clippers — could back in ahead of them.

mjohnson@nysun.com