Celtics  rank first in the NBA in field goal percentage and assists per game, while ranking fourth in points allowed. They’re in the midst of their second five-game win streak of the season, and their four losses are by an average of just 4.0 points. On Wednesday night, they showed an ability to beat a good team (the game Trail Blazers) despite playing poorly. All that adds up to one dangerous team.
2 . San Antonio (15-3): The Spurs  are the biggest surprise of the season, and they’ve done it by reinventing themselves — again. While the dynasty Spurs of yesteryear were more of a slow-’em-down, defensive-minded team, this year’s edition ranks fourth in the NBA in scoring at 106.6 points per game. Maintaining a veteran core, they’ve integrated younger talent like James Anderson, DeJuan Blair , George Hill and Tiago Splitter onto the roster.
3 . LA Lakers (13-6): The Lakers have lost four straight for the first time since acquiring Pau Gasol  three years ago. That’s pretty significant. Speaking of Gasol, as a result of Andrew Bynum ‘s absence, he’s been logging 39.4 minutes per game this season. What’s more concerning for the Lakers is the fact that they’ve struggled to integrate their newcomers into their defensive schemes — and rank 18th in points allowed as a result.
4. Dallas (14-4): Believe it or not, the Mavericks are actually playing defense. Tyson Chandler  has set a tone that’s translated into a third-place ranking in points allowed. And Dirk Nowitzki  continues to be an offensive force. He may look like he’s flopping around the court, throwing up rainbows, but he makes 54 percent of them. As a result, the Mavs already have wins over the Nuggets, Celtics, Spurs, Hornets, Hawks  and Heat.
5. Orlando (14-4): Having won nine of their last 10 games, the Magic are the hottest team in the NBA. The main reason? Their defense. They allow the fewest points per game of any team in the league. Dwight Howard  is making his case for MVP, leading his team in points, rebounds, blocks and steals. Even Rashard Lewis has shown signs of life, as he’s back to shooting 40 percent from beyond the 3-point line.
6. New Orleans (13-5): The Hornets are another team that’s succeeded based on defense (second in points allowed). Notice a theme here? Good teams play good defense. Take note, Hawks and Knicks . Still, after a shocking 11-1 start to the season, the Hornets have fallen back to earth a bit, losing four of their last six games.
7. Utah (15-5): With all the hooplah surrounding the Heat, Lakers and Celtics, the Jazz  are flying under the radar. Rajon Rondo  may have captured much of the talk in the point guard debate during the first month of the season, but Deron Williams (22.1 points, 10.2 assists) is quietly having the best season of any point guard.
8 . Oklahoma City (13-6): After struggling out of the gate with a 5-4 record, the Thunder have won eight of their last 10 and are meeting the high expectations most analysts set at season’s start. Kevin Durant  and Russell Westbrook  have formed the most fearsome scoring duo in the league, averaging 52 points per game between them.
9 . Atlanta (12-7): Despite losing Joe Johnson  to an elbow injury that will cost him 4-6 weeks of the season, the Hawks have found a groove, winning four straight. Johnson’s absence might actually benefit Atlanta in the long run, as they can shorten their rotation while showcasing a lethal Al Horford/Josh Smith combo in the post.
10. Chicago (9-7): The Bulls may have lost (badly) to the Magic in Carlos Boozer‘s return, but don’t expect that to persist. Once they integrate him into the offense and defense, Chicago will be a force to be reckoned with, as the Bulls had won seven of 10 games even before Boozer made his debut.
11. Denver (11-6): The Carmelo Anthony trade talks have subsided a bit. Meanwhile, the Nuggets have won seven of their last 10 games and eight of their nine home games. Remember, with Anthony, this is a 50-win team.
12 . Miami (11-8): The Heat have the fifth-best record in the East. Who could’ve seen that coming? Making matters worse, if they lose to Cleveland in LeBron James ‘ return, their struggles will be magnified even more.
  13. New York (10-9): The good news? The Knicks are scoring 107 points per game (3rd best in the NBA), as to be expected from a Mike D’Antoni-led team. The bad news? They’re also allowing 107 points a game (3rd worst).
14. Phoenix (8-9): Even more drastic, D’Antoni’s former team is scoring the most points while simultaneously allowing the most points in the NBA. Like the Knicks, that puts them right in the middle of the pack.
15. Portland (8-10): The Trail Blazers have lost five straight. Brandon Roy ‘s knees are basically jelly. And Sean Marks is actually playing big minutes for them. Nate McMillan better right this ship — quick.
16. Golden State (8-10): The Warriors are 7-3 with David Lee  and 1-7 without him. That’s how much he means to their success. If he’s healthy, they’re a playoff team, even in the competitive Western Conference.
17. Memphis (8-11): Before losing in Atlanta by three on Wednesday, The Grizzlies  had one four of five — including victories over the Heat, Warriors and Lakers. In that span, Xavier Henry has given them a nice boost.
18. Indiana (9-8): The Pacers are above .500? Yup, and they’ve beaten the Lakers and Heat, too. If Roy Hibbert  continues to play like a top-10 center, they won’t just be fighting for the playoffs — but maybe even a 7 seed.
 19. Houston (6-12): I’ve been waiting for the Rockets to bust out of their slump for over a month now. With wins against the Thunder and Lakers in their last three games, perhaps they’ve finally started to figure things out.
  20. Milwaukee (6-12): So much for that whole “Fear the Deer” thing. Nobody’s fearing the Bucks this year. I’m not sure how a team with seven guys who average double-digit points manages to lose two-thirds of its games.
21 . Cleveland (7-10): The Cavaliers ‘ start was nice and all, but they’re a flash in the pan — just like J.J. Hickson‘s bright yellow shoes. After Thursday’s game against the Heat, they’ll fade back into irrelevance.
22. Charlotte (6-12): The Bobcats play pretty good defense (9th in points allowed), but they just can’t put points on the board. They’re top two scorers — Stephen Jackson  and Gerald Wallace  — are erratic at best.
23 . Toronto (7-11): I still think the Raptors are one of the two worst teams in the NBA, but they’ve won seven games, so I guess I can’t knock them too much. But the Reggie Evans  injury isn’t going to do them any favors.
The Nets  didn’t win their sixth game until Feb. 27 in 2009-10. That’s how bad they were last year. Avery Johnson has made them twice as good this season. Unfortunately, that’s still not very good.
25. Washington (5-12): The Wizards are one of two winless teams on the road. That’s just one more sign of a team that’s led by a 20-year-old. A veteran presence other than Gilbert Arenas  would do this team wonders.
26 . LA Clippers (4-15): Blake Griffin  isn’t just having a Rookie of the Year season — he’s having an All-Star season. And so is Eric Gordon . Too bad that’s all they have, after injuries to Chris Kaman  and Baron Davis .
27. Philadelphia (5-13): The 76ers have won two in a row. That’s best thing you can say about them. With Elton Brand and Andre Iguadola as their top players, you wonder where this team’s leadership comes from.
28. Minnesota (4-14): How is the league’s No. 1 rebounding team so bad? I keep hearing how Darko Milicic  is having a good season. He’s averaging 9.2 points and 6.3 boards. I guess that’s good — for Darko Milicic.
29. Detroit (6-13): After winning four of five games in early November, the Pistons are back to their losing ways, dropping seven of their last nine. This is the second-most self-combustible team in the league behind …
30. Sacramento (4-12): The Kings have so much talent, but little character, as evidenced by DeMarcus Cousins ‘ ejection from a practice. Things don’t get any easier, as they play the Lakers and Mavericks this week.