That the Grizzlies enter Friday tied for fifth in points allowed per possession isn’t that shocking. After all, Memphis finished with the NBA’s No. 7 defense two seasons ago, when head coach Taylor Jenkins’ squad topped .500 and made the playoffs for the first time in the Ja Morant era. Morant and Co. topped that last season, landing fifth — the franchise’s first top-five finish since 2014-15 — as part of a 56-win tour de force that captivated basketball fans before ending in a hard-fought second-round postseason loss to the eventual champion Warriors.

What is notable, though, is how they’ve landed back in that now-familiar top-10 territory. After opening the season a middling 17th in defensive efficiency, Memphis has resumed suffocating opponents, boasting the NBA’s fourth-best defense since Nov. 15; the Grizz are allowing 3.2 fewer points per 100 non-garbage-time possessions than they were earlier in the campaign, according to Cleaning the Glass.

In a related story, Nov. 15 marked Jaren Jackson Jr.’s return following summertime surgery to repair a stress fracture in his right foot. And the All-Defensive First Team big man has wasted absolutely no time swatting away any worries over whether another lower-leg procedure would slow him down as if they were soft layup attempts naively lofted to the rim in his presence:

After ringing up another five rejections in Memphis’ blowout win over the Thunder on Wednesday, Jackson has now tallied 28 blocks in 236 minutes across nine games. His per-game average (3.1) and overall rate (blocking 11% of opponents’ 2-point shots when he’s on the floor) would both lead the league if he’d met the minutes minimum.

Even when Jackson doesn’t get the block, the threat of him unfurling that 7-foot-5 wingspan to erase an attempt still wreaks havoc on would-be scorers. Opponents are shooting a paltry 44.6% at the rim when Jackson’s the closest defender, according to Second Spectrum’s tracking, the second-stingiest mark out of 169 dudes to have faced 50 shots.

And he’s not just staying planted in front of the basket and waiting to lift his arms, either. Jackson’s also calling out screens and directing traffic to help teammates stay attached to off-ball cutters. He’s coming out to the top of the floor to help turn back ball-handlers, closing out hard to the perimeter to make shooters think twice before release and stepping up in help position to douse offensive sparks before they can catch fire. He’s making a difference all over the floor, and it’s reflected in both the eye test and the numbers.

Without Jackson, Memphis held only one opponent (the lowly Hornets) below one point per possession in 14 tries; since he came back, the Grizz have done it three times in 11 games. (That one of those performances — Monday’s 101-93 win over the Heat — came with JJJ and Ja resting underscores the impressive depth of Memphis’ roster … and, for that matter, how dicey things seem in Miami these days.) A starting lineup that didn’t log a minute together last season — Jackson, Morant, Dillon Brooks, Steven Adams and plug-in swingman John Konchar — has been sensational, blitzing opponents by nearly 19 points per 100 possessions, which is nearly twice as much as the dominant Celtics’ league-leading net rating.

The results look familiar: JJJ using his length, quickness, strength and timing to block or change a ton of shots; Memphis clamping down at league-best levels whenever he’s lurking in the paint; and point-of-attack destroyer Brooks (who ranks No. 1 in the NBA in average matchup difficulty, according to The BBall Index’s tracking) is menacing up top, etc. The process of producing them has been different, though, in one interesting way — which is, um, that it hasn’t been as interesting as it usually is.

The recent-vintage Grizzlies have thrived on chaos — on ramped-up ball pressure aimed at creating the live-ball turnovers that allow them to push the pace and getting out in the open court to attack scrambling and unbalanced defenses. Two seasons ago, Memphis finished eighth in opponent turnover percentage, third in points off of turnovers and second in points added per play after a steal; last season, they were fourth in all three categories. Since Jackson’s return, though? Just 21st in forcing turnovers, 20th in points off those cough-ups and 13th in points added per play following a steal.

But while blocks and steals are the loudest ways to end a possession, they’re not the only ones. The quieter driver of Memphis’ defensive turnaround is how much better they’ve been on the defensive glass — and while Jackson himself has long profiled as a below-average defensive rebounding big, his presence has helped.

The Grizzlies are vacuuming up more than 81% of available defensive rebounds when Adams and Jackson man the frontcourt, a league-leading rate. After rim deterrent Jackson and road-grader Adams (one of the league’s preeminent box-out artists) clear the path, one of Memphis’ many backtracking perimeter players — Morant, Desmond Bane and Konchar all grab a higher-than-average share of defensive rebounds for their positions — sprint in to snare the miss and hit the gas.

Play with enough purpose and pace, and you can still blow the other team’s doors off on the break without needing a turnover to give you a head start. The Grizzlies have made a living of that lately, getting into transition after nearly 31% of their defensive rebounds since Jackson came back and scoring nearly 1.4 points per play on those pushes — many of which start with JJJ altering a driver’s shot at the rim, shading over from the weak side to make someone pull up from midrange rather than test him in the lane, or showcasing the agility that enables him to corral a pick-and-roll up top and still get back to protect the paint:

All told, Memphis has posted a 75.7% defensive rebounding rate since Jackson’s debut, third-best in the NBA in that span — up from 71.1%, 16th in the league, with him on the shelf. And as helpful as those rebounds are for igniting Memphis’s transition attack, they also serve a much simpler and even more beneficial purpose: They keep the other guys from getting more easy chances to score on you. The Grizzlies have given up 4.4 fewer second-chance points per game since Jackson came back than they were earlier in the season. Combine that with improved floor balance and better attention to getting back on D after missed shots — through 14 games, Memphis was giving up 1.15 points per possession after an opponent secured the defensive rebound, 22nd in the NBA, according to Inpredictable; that’s down to 1.07, third-best in the NBA, since JJJ came back — and you’ve got a recipe for clamping down that’s not necessarily dependent on fireworks.

Limit runouts, communicate and contest, and go get the ball off the rim: That’s the kind of defense that carries into the postseason, when the game slows down and the pressure cranks up. With Jackson back on the back line, that’s that kind of defense these Grizzlies have. In the short term, it’s helped them keep winning and stay within arm’s reach of the West’s top seed even after losing Bane, their No. 2 scorer, for what might wind up being two-plus months. In the longer view, it’s enough to make you salivate over what Memphis might look like once it finally gets its full complement of dudes back on the court — and to wonder whether this year’s model might have what it takes to push past the second round, into the franchise’s first conference finals in a decade … and, just maybe, even further than that.