Buy or sell: Nuggets are a bigger Warriors threat than Houston

Throughout the season, we'll check in on which big NBA trends are real or not.

First up: Are the undefeated Denver Nuggets scarier foes for the Golden State Warriors than the Houston Rockets are? And are Anthony Davis' New Orleans Pelicans going to remain the best offense in the NBA?

Let's break this statement into two parts:

1. Are the Nuggets legitimate contenders this season?

2. Are the Rockets no longer fully at that level?

I'm selling on the latter. Last season, the Rockets finished 16 games better than any other Western Conference team not named the Warriors, while posting the best point differential in the NBA. From that team, they lost two big wings in Trevor Ariza and Luc Mbah a Moute -- valuable contributors, though they finished 61st and 103rd, respectively, in defensive real plus-minus ( RPM). Four games -- including a dud against the Pelicans and two losses without Chris Paul -- shouldn't be enough for us to believe that the Rockets are about to drop from a  top-seven defense last season to well below average now.

This Houston team still has its core pieces and should reclaim a gap over the non-Warriors squads in the West.

That said, I am buying the Nuggets as legitimate contenders to finish with first-round home-court advantage, even though they missed the playoffs last season.

Denver is built around one of the best players in the NBA in Nikola Jokic. Jokic was a per-minute wonder as a rookie and has maintained his stellar impact with more minutes, finishing fifth in the NBA in RPM last season.

He is the focal point of the Nuggets' offense, often playing as a point-center, and his perfect triple-double on Saturday -- 35 points (11-11 FG), 11 rebounds, 11 assists, four steals, one block and zero turnovers -- was not a fluke. He is a consistently versatile offensive threat, powering an attack that has finished in the top six in offensive rating the past two seasons.

Of course, the biggest difference for this team has come on defense. After finishing 25th and 29th in team defensive rating the past two seasons, the Nuggets are all the way up to No. 2 now.

One reason for that improvement: the health of Paul Millsap, who finished top-15 overall in defensive RPM in his past two seasons as a member of the Hawks before injuries limited him to 38 games in his debut Denver year. Now healthy, he's giving the Nuggets a solid defensive anchor to build around. They've posted an astonishing 88.6 defensive rating with Millsap on the court. That jumps to 106.1 when he's off -- and 106.1 would still rank in the top 11 among all teams right now.

Surely some regression is coming. The question is, how much? According to Second Spectrum tracking data, the Nuggets are forcing the sixth-toughest looks in the NBA. But that's in a small sample, and 34.4 percent of opponent shots have come on open or wide-open 3s -- fifth-most in the league, per NBA Advanced Stats. The fact that Denver is holding opponents below 31 percent shooting from deep is most likely attributed to randomness that is bound for a correction.

Still, slide the Nuggets back down to an average defense, and their sustainable offense keeps them competitive. If they're legitimately above average -- a possibility with a healthy Millsap -- then this team can challenge for 55 to 60 wins.

Overall, this is a soft sell. The Nuggets are a potential top-four team out West, but they have to prove a stable defensive level before they become true Warriors challengers at the level of the Rockets.

The Pelicans have averaged 132 points per game and 122.2 points per 100 possessions, both top marks in the NBA. They have achieved these numbers with a unique, inside-out offensive approach that features three big men as their leading scorers and most-reliable 3-point shooters, with two guards who have pushed the pace and distributed the rock. They're rolling without the perimeter scoring typical in today's NBA.

Some aspects of this start are sustainable, such as the fast pace (currently fourth, after leading the NBA last season) and the offensive mismatches created up front by MVP candidate Anthony Davis, perimeter threat Nikola Mirotic and combo big Julius Randle.

But this current level of offensive excellence -- no team has posted an offensive rating above 115 in the past decade -- is likely to slip as the schedule evens out. The Pelicans' first three games have come against the Sacramento Kings (27th in defensive rating last season), the LA Clippers (20th) and a sluggish Rockets team.

Mirotic (33.1 points per 36 minutes, 64.5 true shooting percentage) and Randle (28.8 points per 36 minutes, 64.4 true shooting) are scoring at gigantic career outlier rates and efficiencies, which almost have to regress. Even Davis -- who actually could sustain marks near his current 30.9 points per 36 minutes at 66.0 true shooting -- is bound to cool way off from his outlier 3-point-shooting rate of 75 percent (!) efficiency on 1.3 attempts per game.

On the bright side, Jrue Holiday was a key offensive engine in the playoffs, and he has started the season in a big shooting slump with what would be career lows of 11.5 points per 36 minutes at 38.1 true shooting. He should regroup and help the team maintain as the potent big men slow down.

This is primarily a sell because the Pelicans don't ultimately have the consistent 3-point-shooting volume to compete with teams such as the Warriors and Rockets. (Somehow, they're pulling this off while ranking 27th in 3-point attempts per 100 possessions.) New Orleans' big men will fall back to some level of humanity in their scoring. But they have better offensive talent and, importantly, a much better fit than they've had in seasons past. They're top-10 in shot quality, per Second Spectrum, and should comfortably finish as a top-10 offense.