Okay, now it gets serious.

For most of the NBA, the first half of the season is a feeling-out process. Players find out the pecking order on the roster and figure out what they have to do to get minutes. Executives determine which players belong on the team and which should be traded. Coaches decide who should be in the rotation and who shouldn’t (well, all of them except Larry Brown, anyway). Like the first few miles of a marathon, it’s not holding the lead that matters but positioning yourself for the finishing kick.

Once Thursday’s trade deadline passes, however, it’s go time.A few teams already left for dead will focus on next year, of course, and the Knicks are certainly among them. But for the rest of the league, there’s no more time to wait.With roughly 30 games remaining for each team and no more roster moves to make once the deadline passes, the only item on the agenda is to win as many games as possible.

In the big picture, it’s all about a battle for seeding in the playoffs. Last season, for instance, home court advantage helped San Antonio overcome Detroit in the second half of the deciding Game 7, and two weeks earlier it nearly allowed a battered, weary Miami team to knock off the Pistons in the conference finals.

That’s not the only advantage seeding can confer, however. For one example, the NBA’s bizarre playoff setup ensures that earning the sixth seed in a conference produces a great opportunity for a first-round upset – as it did for Indiana against Boston last year. Conversely, a fifth seed is best avoided, since that produces a matchup against the no. 4 seed – and probability says the no. 4 team will have a better record than at least one of the division winners seeded ahead of it. The Rockets found this out last season, when they played over their heads for six games and still got blasted to smithereens by Dallas in Game 7.

Similar battles are shaping up for this year’s postseason, which is why jockeying for position in the season’s stretch run is so important. With that in mind, let’s take a look at some of the most prominent races we’ll be watching during the second half of the season.

PISTONS VS. MAVERICKS AND SPURS

The Pistons would have to completely collapse to avoid owning homecourt advantage in the Eastern Conference, but that’s not the prize they’re after. Detroit felt it would have won the title a year ago had the seventh game of the Finals been held at their raucous Palace rather than at San Antonio’s SBC Center (as it was then called), and their focus this year has been on earning the league’s best record and playing the season’s last game in Motown.

The Pistons looked to be running away with the league’s best mark when they raced out to a 35-5 start, but a few slip-ups before the All-Star break have put them just a game and a half in front of Dallas. That’s a small margin once one considers that the two teams play again and that Dallas, by virtue of winning their first meeting, would own a tiebreaker edge with a second win.

Lurking just behind the Mavericks are the San Antonio Spurs, who trail the Pistons by two and a half games. The Spurs, however, have a long history under coach Gregg Popovich of hitting their stride in March – just as they did last season en route to the title. The Spurs are in a worse position as far as home court is concerned, though, because Detroit already owns a head-tosweep and the tiebreaker edge that comes with it.

MAVERICKS VS. SPURS

Of course, we needn’t look ahead to the Finals to realize the importance of home court to Dallas and San Antonio. Because of the league’s shortsighted division structure and the fact that both teams are in the Southwest division, one of them will end up as the no. 4 seed in the Western Conference and play a much tougher slate in the postseason. Additionally, the two teams will almost certainly meet in the second round, and home court for that showdown is obviously highly coveted.

At the moment, the Mavs own a one-game edge on San Antonio, but two meetings in March will likely determine ultimate division champion. The first one is in two weeks in San Antonio, and as luck would have it, it will be nationally televised. The second one is in April, and unfortunately for the Mavs, that one is in San Antonio as well – perhaps giving them a little preview of the importance of home court.

NUGGETS VS. JAZZ AND T-WOLVES

None of these teams has played very well this year, but nevertheless, one of them will be rewarded with the “Northworst” Division crown and the no. 3 seed in the West. Conventional wisdom says the Nuggets will pull away now that Marcus Camby is back, but nobody confidently calls Camby “healthy” without double-checking the news wires first.

Additionally, both Utah and Minnesota have made additions for the stretch run. The Jazz returned highscoring forward Carlos Boozer just before the break after nearly a year of inactivity, while Minnesota’s trade of Wally Szczerbiak for Ricky Davis also added depth thanks to throw-ins Mark Blount and Marcus Banks.

While the victors earn the no. 3 seed, they still have to go on the road in the first round if, as expected, the no. 6 team has a better record. And for the loser, it may be a drop to the lottery because chances are good that only one team from this weak division will make the postseason.

L.A. CLIPPERS VS. HORNETS AND GRIZZLIES

This one is an interesting three-way race because everybody wants to finish right in the middle. Let me explain. Right now the Clippers, Grizzlies, and Hornets all are within a game and a half of each other for the fifth, sixth, and seventh seeds in the West. But the sixth seed, with its accompanying firstround match against the Northworst champ, is far more desirable than either being fifth (and having to face Dallas and San Antonio in succession) or seventh (and facing Phoenix with Amare Stoudemire).

At the moment, the Hornets are the ones in the catbirds’ seat, but the Grizzlies’ home-heavy schedule down the stretch should allow them to overtake New Orleans/Oklahoma City for the coveted no. 6. The question is whether they’ll hang on to it, or if the Clippers embark on a strategically timed slump down the stretch to magically fall behind Memphis in the standings. For the Grizzlies, who have never won a playoff game thanks to some horribly unfavorable first-round pairings, it would be par for the course.

Mr. Hollinger is the author of the 2005-06 Pro Basketball Forecast. He can be reached at jhollinger@nysun.com.