The Wolves and Hornets are the NBA's most improved teams. Are they for real?

We are now past the quarter-point of the NBA regular season. If the season were a high school mile, we'd have gone around the track once. If you remember racing the mile in high school, you remember that by the time everyone has done one lap, the stratification has begun. You have a pretty good sense by then who is fast and who is not.

Likewise, the general shape of the NBA season is forming. We know who is way out front (Golden State, San Antonio) and who is straggling way behind (Philadelphia, the Lakers). It's everyone in the middle -- that vast pack trotting within a few lengths of each other -- that's still the mystery.

Most interesting to me are those teams in the middle that have improved or devolved the most. That slow kid who is fast now, or the former speedster who is stuck in mud. The teams that have fallen off spectacularly have been well-covered. The Pelicans (-8.3 points per 100 possessions), Rockets (-8.2), Grizzlies (-7.9), Bucks (-7.1) and Wizards (-5.9) have each gotten worse on both ends of the floor, though Milwaukee and Houston can blame their defenses for the bulk of the regression.

But among the teams that have improved the most in terms of net rating -- which is scoring margin over 100 possessions -- there's a definite skew in each case.

Four of the five most improved teams in terms of net rating this season can credit huge improvements to their defenses. The outlier -- Charlotte -- has also seen its defense improved modestly, though its rise is more dependent on a massive leap in offensive efficiency. For the other four teams, it's been all about the defense.

This raises two questions for these teams: Is this improvement sustainable, and is it enough to compete this year?

WOLVES

IS IT SUSTAINABLE? The important thing to remember about Minnesota is that it was absolutely dreadful last season, particularly on defense. The crazy improvement this season hasn't launched the Wolves into elite status. Minnesota ranks No. 18 in defense right now. As such, the improvement certainly appears sustainable.

The question in this case is whether it can get even better.

That's a tricky question because the best defensive lineups Minnesota run feature Kevin Garnett, who is closing in on retirement. His role is to impart wisdom on the next defensive anchors of this club -- Karl-Anthony Towns and Gorgui Dieng -- and to lead by example. He's doing that. The Wolves' most-used lineup this season is terrific on defense. It features Garnett, Towns, Andrew Wiggins (a plus defender who could become a great defender), Ricky Rubio (another plus defender) and Tayshaun Prince, who, like Garnett, is on his way out of the league.

Minnesota's also gotten good defensive minutes out of Nemanja Bjelica, Dieng and Zach LaVine, so there really is some potential for an even stronger unit. But that will depend on how the rotations shake out and in particular whether Towns and Wiggins reach elite defender status.

IS IT ENOUGH TO COMPETE THIS YEAR? Probably not. Though surprisingly competitive in a surprisingly mediocre West, Minnesota currently sits at No. 10 in the conference standings after 21 games. The silver lining is that Minnesota is dreadful (3-9) at home but good (6-3) on the road. If the Wolves can start winning at Target Center and keep up a solid road record, that could change the calculus and launch Minnesota into the playoffs for the first time in a decade.

HORNETS

IS IT SUSTAINABLE? The Hornets' offense is better for a few reasons. For starters, Lance Stephenson, one of the least productive starters in the NBA last season, is gone. Just freeing up those minutes for anyone else is a boon. Those minutes (plus those recovered from Gerald Henderson) have gone to a mix of Jeremy Lamb and Jeremy Lin, who have been competent. (Lamb has actually risen to the level of solid, a vast improvement over Stephenson.)

The bigger change is that Nicolas Batum is playing like an All-Star, and offensively deficient Michael Kidd-Gilchrist is out with an injury. That's been a huge boon on offense -- Batum is a shooting threat on a team that has been short of them. The loss of MKG hasn't mattered too much on defense.

Batum's excellent play seems somewhat unsustainable simply because he's a veteran with a larger offensive role than he's ever had ever before. There's no evidence in his record that he can mix this high volume and efficiency for a full season. We'll see. I'm also concerned about the defensive ramifications of a stretchier front line featuring Cody Zeller, Frank Kaminsky and Spencer Hawes in rotation. It's working on both ends, but on paper that's a unit that should be getting shredded by quick or brawny big men. As Charlotte transitions away from Al Jefferson (who has been injured and is now suspended), that's something to watch.

IS IT ENOUGH TO COMPETE THIS YEAR? Absolutely. Charlotte is in the top 10 in both offense and defense, and Batum is the only guy really playing well above expectations. (Lamb is another candidate for that distinction, but his production isn't outrageous.) For all the talk about the rise of the East, it's still wide open. No team, not even Cleveland, has distinguished itself. Charlotte is No. 2 right now, and there's plenty of space for the Hornets to fit in somewhere in the 2-8 range.

HEAT

IS IT SUSTAINABLE? You'll never convince me that anything relying on Hassan Whiteside is sustainable. Sorry. The Heat actually have this one killer lineup (their third most used) that just slays on defense. It features Whiteside (who, jokes aside, has been a phenomenal value), Luol Deng, Justise Winslow, Dwyane Wade and Goran Dragic. That doesn't look like an elite defensive lineup on paper, but all things are possible through Whiteside. Everyone can guard their man close and rely on the big man to sweep anything in the paint. The other top Heat lineups feature Chris Bosh and Whiteside up front in more traditional roles. They work very well together.

What's surprising is the team's mediocrity on offense. Miami's been awful from behind the arc despite taking fewer threes than most teams. The offense has become downright Memphian. No regular other than Tyler Johnson is shooting better than 36 percent, and most lineups feature at least two, if not three, poor deep shooters. Deng and Dragic have been abnormally bad from distance and Dragic's production in general has been a real disappointment.

IS IT ENOUGH TO COMPETE THIS YEAR? If Dragic's production rises to normal levels, if Bosh, Deng or Josh McRoberts can shore up their shooting, if Wade can stay healthy and if Whiteside can continue to be one of the best defenders in the NBA, this team can absolutely challenge for the East. The elite defense, No. 2 in the league, is a game-changer.

MAGIC

IS IT SUSTAINABLE? It's the Scott Skiles factor. Of course it's sustainable ... for 2 1/2 years, until everyone tunes him out. Like clockwork.

That said, this team has a grip of high-potential defenders and pretty good depth. One of the keys seems to be where Tobias Harris lines up. The high-minutes lineups that feature Harris at small forward with two bigs (some combo of Nikola Vucevic, Channing Frye and Andrew Nicholson) fare well on defense. When Harris is the power forward with three guards and one other big, Orlando's defense is typically pretty bad.

That makes it somewhat mysterious as to why Harris and Aaron Gordon (the team's most promising PF in most folks' opinion) play so little together. Gordon's only been on the court for 12 percent of Harris' minutes. Skiles has been using Gordon at the three rather frequently despite Gordon's lackluster stretch qualities. The rotation is working: Orlando is No. 6 in defense. But you do wonder if they'd be better long-term if a Harris-Gordon-Vucevic front line had a regular presence. No offense to Frye and Nicholson, who stretch the floor well (important given the team's lack of backcourt shooting), but Gordon projects as a far superior defender.

But to answer the question: yes, this team has the goods to remain very good on defense and field a not-hopeless offense.

IS IT ENOUGH TO COMPETE THIS YEAR? It's certainly enough to get into the playoffs, which is a stated goal of the franchise. Orlando is No. 13 in the league in net rating, and eighth in the East. It's hard to see the offense doing enough to launch the Magic into the Miami-Charlotte-Toronto conversation barring continued excellence from Evan Fournier or a clicking moment for Victor Oladipo (who's been good off the bench but is still below 40 percent from the floor) or Elfrid Payton. Playoffs? Doable and maybe even probable. Home court in the first round? Nah.

KNICKS

IS IT SUSTAINABLE? All things are possible through Kristaps Porzingis.

IS IT ENOUGH TO COMPETE THIS YEAR? All things are possible through Kristaps Porzingis.

But seriously: Kristaps Porzingis changes everything. His surprising NBA readiness gives New York a defensive anchor, which is vital given Jose Calderon's loose perimeter defense. Robin Lopez and Arron Afflalo have been big defensive upgrades, as well, and oddly the Knicks are in a position where the help they need is really on offense. Carmelo Anthony is still forced to do a little too much because there isn't a ton of shot creation around him. You really don't want Lopez, Afflalo, Porzingis or anyone but Calderon creating offense regularly. That puts a lot on Melo's shoulders. Luckily, he's always happy to take on that offensive burden. It just doesn't result in a good-looking (or performing) offense.

Porzingis has shown some flashes in the post, Lopez is a pretty good passer and Melo can actually pass really well when he has clear lines to open shooters. But in total, it's just not enough on offense without another creator or more shooting. Given Porzingis' defense and these issues, it really would have paid off if the Knicks had been able to land Greg Monroe. Alas. The Knicks don't look quite good enough to make the playoffs in a deeper East, but one trade could change that. We'll see.