Much like the calendar, the NBA season has four distinct seasons. There’s the off-season, which is spent signing free agents, making trades, and building for the coming year. There’s the beginning of the season, which lasts from opening day until roughly New Year’s Eve, when everybody is figuring out what they’ve got. And later on, there’s the “winning season,” which runs from late February to the last day of the Finals — when the main contenders gear up to make up their push.

In between those last two seasons, however, is something called Trading Season. It doesn’t have a defined beginning, but it begins some time around New Year’s Day. It does have an official end, however — the trade deadline on February 22. This line in the sand serves as a useful bulwark against excessive procrastination, as teams spend the weeks leading up to the deadline discussing one deal after another, but generally don’t pull the trigger until the clock is about to strike midnight (figuratively, that is — the real deadline is 6 p.m. EST).

This year trading season kicked off a little early, as the Philadelphia 76ers jettisoned Allen Iverson before Christmas when he became fed up with his awful supporting cast. Nonetheless, it won’t get into full swing until later this month, when teams who are in the playoff race start making serious proposals and those who are out of it figure their best options for the future.

But with nearly two months of rumors and innuendo waiting just around the corner, it’s time to size up the situation. So with just 50 shopping days left, here’s a look at the players most likely to pack their bags this Trading Season.

VINCE CARTER OR RICHARD JEFFERSON, NETS: With Isiah Thomas’s checkbook privileges apparently revoked, this may be the midseason that the team across the river is the one making the big splash.

I’ve been arguing since Nenad Krstic went down that it was time for the Nets to consider a major makeover. If they go that route, trading Carter seems the easiest way to do it since since he’s in the final year of his contract. As far as possible partners, Orlando makes the most sense — the Magic could use Carter’s Bird rights to re-sign him and still keep Darko Milicic this summer, Grant Hill’s expiring contract can offset Carter’s in a trade and give the Nets cap relief, and the Magic have several good young players who could be part of the ransom.

But one sage in the know advised me of a different possibility — trading Jefferson, whose cap number is much easier for other teams to match. It would have to be the right offer (i.e., one involving Kevin Garnett or a similar wattage of superstar) because the Nets would be risking losing Carter for nothing in the off-season, but don’t automatically presume that if the Nets blow things up, Carter’s the first one out the door.

KEVIN GARNETT, T’WOLVES: Speaking of which … Garnett hasn’t publicly demanded a trade, and as long as the Timberwolves stay alive and kicking in the Western Conference playoff race he probably won’t. But should this team hit a rough patch, it’s hard to envision Garnett deciding to stick around for another lottery run.

Additionally, it’s in the T’wolves’s best long-term interests to trade him while his value is still high so they can get on with the rebuilding process. Their veteran-laden roster is unlikely to improve much in coming seasons, while Garnett’s trade value drops with each week that they dither. As a final incentive, Garnett can opt out of his contract in 2008, meaning the T’- wolves could be left high and dry if they can’t move him first. Should he come on the market, the Bulls will be waiting with several enticing prospects in hand, but every team in the league will at least make a courtesy call.

ANDRE MILLER, 76ERS: The rebuilding Sixers don’t seem to have an obvious need for a soon-to-be 31-year-old guard with a hefty contract, so the recently acquired Miller shouldn’t start house shopping in Philly just yet.

There’s a small catch, however — Miller can’t be dealt as part of a package until just a few days before the deadline, although he can be traded alone prior to that date. Philly would be most likely to deal him if an expiring contract comes back, but those kinds of deals can be hard to work out. Cleveland and Miami are obvious suitors because of their glaring needs at the point, but may not have the goods necessary to pluck Miller from the Sixers.

COREY MAGGETTE, CLIPPERS: Maggette is a scoring machine but has been underutilized in L.A. because of dissatisfaction with his defense. As a result, both player and team are ready to move on. Given his reasonable contract and prodigious output, I’m anxiously awaiting to see where he ends up, because I have a feeling this one could turn out to be a steal of a trade for the team that acquires him. Maggette has his weaknesses, but guys who can get you 20 at a high rate of efficiency don’t grow on trees. I couldn’t hazard a guess as to his next stop, especially since the Maggette-for-Artest rumors have died down. Speaking of which…

RON ARTEST, KINGS: The Kings have belatedly realized that Artest is not only crazy, and also selfish — he continues to hoist terrible shots and complain about his role. As a result the Kings are considering moving him, but there’s a problem: Few teams have the stomach to deal with Artest, so the Kings are finding an even more tepid market for his services than the Pacers did a year ago. Nonetheless, a couple of clubs are in dire enough straits to gamble on Artest’s character, including the aforementioned Clippers, so the Kings may yet be able to dump their most talented but most troublesome player.

JAMAAL MAGLOIRE, TRAIL BLAZERS: It’s always a warning flag when a team starts giving big minutes to a player with an expiring contract even though he isn’t performing well. In this case, Magloire is fairly obviously being showcased for teams in search of big man help, as Portland has firstround pick LaMarcus Aldridge waiting in the wings once it unloads the veteran big man. Portland may have trouble finding a taker, however, as Magloire has slipped noticeably and most of the contending teams already have solid center rotations.

BONZI WELLS, ROCKETS: I think it’s safe to say the Wells-Van Gundy marriage isn’t working out, and with Luther Head playing well and Kirk Snyder due to come back from injury in a few more weeks, it may be time to convert Wells into some much-needed point guard help. Wells can’t be traded until Jan. 5, but look for the Rockets to listen to any and all offers starting then. Detroit has always been fond of Wells and is probably more anxious than ever to replace Carlos Delfino after his hare-brained game-losing foul against the Pacers last weekend, so that’s one obvious possibility.

jhollinger@nysun.com