Should we believe in the Nuggets' defensive turnaround?

Back on Dec. 14, the Denver Nuggets claimed a piece of NBA history by scoring a modern-day record 98 paint points en route to a 141-128 win over the Washington Wizards. The game perfectly encapsulated the Nuggets at that point in the season: They couldn't be stopped, nor could they get stops. Afterward, head coach Michael Malone acknowledged the incredible offensive achievement but in the same breath sounded the alarm about his team's punchless defense.

"You can win regular-season games like that, but you're not gonna win a playoff series if your recipe is to outscore teams," Malone told reporters. "I don't like winning games when it's just offense, and that's gotta change at some point. ... It's going to bite us in the butt here soon."

Sure enough, two nights later, the Nuggets suffered arguably their worst loss of the season - a 126-108 beatdown at the hands of a Los Angeles Lakers team that played without Anthony Davis for the entire second half. Malone was exasperated.

"Everything we stressed going into the game, we did nothing to stop any of those," he said. "(We gave up) 64 in the paint, 30 in transition, 18 on the glass. ... Like, what are we doing out here? Are we just wasting our time, going through the motions?"

The Nuggets were a respectable 17-11 at the time thanks to their Nikola Jokic-led offense. But they ranked 28th in defensive efficiency, allowing more than 115 points per 100 possessions. Their pick-and-roll coverage was getting picked apart. Their bench was bleeding points. They were getting lit up from 3-point range, gashed at the rim, and torched in transition. It wasn't exactly a recipe for title contention.

The roster makeup never screamed defensive juggernaut, but the extent of the Nuggets' ineptitude at that end was mystifying considering they had quality individual defenders such as Aaron Gordon, Kentavious Caldwell-Pope, and Bruce Brown logging heavy minutes, and that their other key contributors (with a couple of notable exceptions) were about average.

"There's no way in hell we should be 28th in defensive efficiency," Malone said. "You can't tell me that in my eight years in Denver, this is our worst defensive team. No one can ever convince me of that."

Once again, the coach proved prescient. Since that Lakers loss, the Nuggets are 11-2 with the league's second-best defensive rating (109.8). That surge has them tied atop the Western Conference standings and up to 19th on defense for the season. So, what's powered that dramatic turnaround? And can it hold?

Let's get this out of the way first: When a bad defensive team suddenly becomes good, opponent shooting variance is almost always a significant factor. That doesn't tell the entire story here, but it certainly tells part of it. Opponents have hit just 32.2% of their threes during this 13-game stretch (including just 28.1% from above the break), the lowest percentage any team has surrendered over that timeframe. Opponents have also hit just 40.5% of their non-rim 2-pointers, the fifth-lowest mark allowed during this stretch. Simply regressing those numbers to league average would put Denver's defense back around where it was early on.

But that doesn't mean there haven't been encouraging signs of growth and a much better defensive process overall. The Nuggets have been far more proactive and connected with their rotations, more adept at helping the helper, and a bit more flexible with their coverages. (More on that in a minute.) Denver's base pick-and-roll scheme brings the screen defender (typically Jokic) up high and momentarily puts two guys on the ball, which places a ton of pressure on their low man to tag the roller and recover out to the perimeter. That's been a major area of improvement recently, with Gordon and Brown doing a lot of the heavy lifting.

At the rim, where teams tend to have more control over how their opponents shoot, the Nuggets have shaved their field-goal percentage allowed from a disastrous 70.5% down to 68.4% during this run, according to Cleaning the Glass. That doesn't seem like much, but it represents a jump from 29th in the league to 16th because of the way offense keeps trending up.

It's worth noting that Michael Porter Jr.'s return from a heel injury coincided almost exactly with the team's defensive upswing, and there's a genuine correlation there. That might be hard to believe given Porter's obvious warts, but simply having his 6-foot-10 frame on the back line makes a big difference in short-roll deterrence, especially when Gordon is the guy defending the ball-handler in the pick-and-roll.

On top of simply bringing size, Porter has improved immeasurably as an off-ball defender. He's gotten a much better feel for the timing of those low-man rotations and for playing between two guys when zoning up the weak side. He's making crisp X-outs and balanced closeouts:

Meanwhile, Jamal Murray's return to form as a stout one-on-one defender and screen navigator has really fortified things on the perimeter, while Caldwell-Pope has proved to be an invaluable addition on that front.

Here's an example of all the pieces working together in harmony from the Nuggets' epic beatdown of the Clippers last week:

The Clippers run a double ball screen; Gordon switches the first one, Jokic shows high on the second, Porter pre-rotates to tag the roll, Caldwell-Pope snuffs out the skip pass with a long closeout to the corner, Porter completes an X-out to take away the above-the-break three, Gordon forces Paul George into a contested pull-up mid-ranger, and Jokic caps it off by inhaling the rebound.

The Nuggets have also meaningfully cut down on opponent 3-point attempts, without a corresponding bump in rim volume. Instead, they've managed to reroute a chunk of those threes into the mid-range area for long twos and floaters.

And if you want to argue that their opponents' sudden decline in long-range accuracy isn't a fluke, point to the fact that the Nuggets are forcing teams to dribble into more of their shots than they were before and are allowing the 10th-fewest wide-open threes per game since the Lakers loss, 2.1 fewer than they were conceding up to that point, according to NBA Advanced Stats.

Anecdotally, it feels like many of the threes they've allowed lately are of the contested variety, more a product of stagnation than rotation-beating ball movement:

Malone has also tinkered with different schemes that change the way Jokic operates within the defense, sprinkling in more zone, pre-switching, and "next" help in order to keep him closer to the basket and out of high ball-screen action. That was a particularly prominent tactic in the Nuggets' win over the Memphis Grizzlies last month, a game in which Denver allowed just 91 points. It also helped the Nuggets flip a game against the Cavaliers a couple of weeks later, a would-be schedule loss that turned into a rousing win on the second night of a back-to-back:

The Nuggets don't like to use Jokic in a drop because containing the ball while backpedaling is probably the thing he struggles most with defensively. Having him up at the level utilizes his size and quick, sticky hands in a more productive way. But zones and pre-switches can work well for Jokic because they allow him to be a disruptor near the basket from a stationary position:

In that Grizzlies game, the Nuggets did also mix in a lot of standard drop coverage for Jokic. They haven't returned to that well too often since, but they should feel more comfortable doing so now that they have guys they can trust to fight over screens and stay attached to ball-handlers (i.e. Caldwell-Pope, Brown, and more recently Murray). That simply hasn't been the case for their point-of-attack defenders in recent years. For a defense that's skewed one-dimensional, having those wild cards to play can be extremely important.

Even when their opponents' shooting regresses to the mean, the Nuggets can hang their hats on their ability to guard without fouling and clean the defensive glass. That second point is particularly important, and it's powered by Jokic's underrated ability to get out to the perimeter and veer back in time to snatch the ball off the rim with his giant meat paws. All told, the starting lineup of Murray, Caldwell-Pope, Porter, Gordon, and Jokic has a 104.5 defensive rating, which is miles better than the Cavaliers' league-leading mark for the season and second-best of any five-man combination that's played at least 200 minutes. (That group's plus-16.6 net rating also ranks second, behind only the Warriors' starters.)

The bench is where the struggles have been most pronounced, but that's slowly getting smoothed out as well. Pulling DeAndre Jordan from the rotation in favor of Zeke Nnaji has helped stabilize the second unit's defense, even though it leaves that group a tad small up front. Vlatko Cancar has taken Jeff Green's spot with those units while Green recovers from a fractured hand, but he'll be hard to bump if he continues to shoot the ball and compete on defense the way he has recently.

Bones Hyland remains a glaring minus, and that's something Malone will have to wrangle with when the games start to really matter. His preferred transitional lineup right now is a Murray-and-bench group, which keeps the offense afloat while Jokic sits but may not be tenable defensively. In 236 minutes with both Hyland and Murray on the floor, the Nuggets have surrendered 124.1 points per 100 possessions. Malone has had Gordon on the court with Jokic off for just 77 minutes this entire season. Although the defense in those minutes hasn't been good either, you wonder if at some point he'll give it a longer look.

There are other red flags that support Malone's earlier concerns about postseason viability. The Nuggets continue to rank dead last in transition defense (135.4 points allowed per 100), and they're getting burned particularly badly off of live-ball rebounds, per Cleaning the Glass. Neither of those things has improved during this run. (It does help that the Nuggets simply don't miss many shots; as a result, they're actually one of the league's best teams at preventing opponents from getting out on the break.)

For all Porter's strides as a help defender, his on-ball work is still a mess, and the Nuggets encounter problems when teams involve him in ball screens. We've seen teams like the Celtics opt to attack him instead of Jokic, spacing the latter out to the corner and forcing him to make the help-and-recover decisions while Porter tries to contain the ball. We've also seen teams exploit his poor screen navigation by using double-drag actions that force him to switch onto the ball and then navigate the ensuing pick. Denver should keep experimenting with schemes that keep not only Jokic but also Porter out of those actions on the perimeter.

Jokic's rebounding and at-the-level activity make up for a lot, but his lack of lateral agility (ball-handlers still turn the corner on him regularly) and poor rim protection still make him a less-than-ideal defensive anchor on the whole. Plenty of great rim-protectors have mastered the craft without the benefit of elite vertical athleticism, but Jokic hasn't gotten there because he's frequently late and noncommittal with his back-line help. That largely has to do with him prioritizing rebounding position over shot contests, and given how toothless his contests can be, that's probably the right approach. It doesn't change the fact that scheming around his limitations against elite playoff offenses will be a significant challenge.

And yet, the Nuggets' offense is so good that it might not matter. Their defense only needs to be passable for them to contend, and what they've done this past month, even if it's unsustainable over long periods, has proved they're at least capable of being good enough on that side of the ball.

As Malone crowed after the Nuggets kickstarted this turnaround a month ago with their first in a long line of acceptable defensive showings: "I'm gonna stick that in a pipe and smoke it."