Brook Lopez's interior defense remains the Bucks' secret sauce

Arguably the biggest concern for the Milwaukee Bucks coming into this season was the age and health of their starting center.

Brook Lopez has been integral to everything the Bucks have done - especially defensively - since he signed as a reclamation project for the bi-annual exception back in 2018. His arrival coincided with the hiring of coach Mike Budenholzer, and Budenholzer immediately set about reconfiguring the team's scheme at both ends of the floor in a way that leaned on Lopez's paint-protecting abilities on defense and tapped into his dormant value as a floor-spacer on offense.

Suffice it to say, the Bucks wouldn't have been able to amass the league's best record in both 2018-19 and 2019-20, nor won the championship in 2021, without him.

That's why there was a tinge of worry for the team entering a campaign in which Lopez will turn 35 with about 30,000 NBA minutes on his 280-pound body and a back surgery that cost him nearly all of the 2021-22 campaign. With him sidelined for all but 13 regular-season games, the defense that had been the best in basketball for much of the previous three years slumped to 14th in points allowed per possession. He returned in time for the postseason and helped that defense morph back into one of the NBA's top units, but there was justifiable uncertainty over his ability to sustain his level of play.

Well, seven games into the new season, Lopez's interior defense somehow looks more imposing than ever. The Bucks are 7-0 despite the absence of Khris Middleton because they once again own the best defensive rating in the league. Lopez has arguably been the biggest driver of the team's success on that side of the ball; they've allowed 20.4 fewer points per 100 possessions with him on the floor, per Cleaning the Glass.

One of the chief worries about aging big men is load time. The creakier a player gets, the longer it takes him to get off the ground. For a rim-protector, taking a long time to get off the ground significantly narrows the margin for error when it comes to timing shot contests. Lopez, though, has long been one of the league's most patient and intuitive practitioners of verticality. He knows how to let his size do the work around the basket, which means he rarely leaves his feet before he has to. He's still seemingly able to bounce around like a young man (albeit one who was never particularly explosive to begin with).

Look how quickly he's able to get off the ground on his second jump here, allowing him to deter Dejounte Murray's layup and recover in time to block Clint Capela's dunk attempt off Murray's lay-down pass:

You might also worry about a player's ability to pop in and out of a deep defensive stance after dealing with back issues (see: Michael Porter Jr.), but Lopez has had no such issue. You can see how his low crouch here allowed him to nimbly change direction and meet Murray at the rim after Murray rejected the screen and exploded downhill:

Lopez is blocking a league-high three shots a game, but as ever, his impact is as much about the shots he prevents from happening as it is about the ones he alters or swats away. His presence completely transforms Milwaukee's defensive shot profile. Opponents shoot significantly less frequently at the rim and from floater range when he's out there, and no player has had a bigger effect on the frequency of long mid-rangers his team coaxes (a 6.4% uptick with him on the court), according to Cleaning the Glass.

As they've done a few times throughout the Budenholzer era, the Bucks came into this season with a broad new schematic mandate - one that yet again put Lopez's abilities front and center. The system Budenholzer installed upon his arrival placed a huge priority on protecting the basket, and, thanks largely to the combined efforts of Lopez and Giannis Antetokounmpo, the Bucks were able to do so to a near-historic degree. But the cost of their overwhelming interior focus was that they conceded more 3-point attempts than any team in basketball over the last four years. This season, they aimed to strike a different balance by placing more of an emphasis on defending the 3-point line.

You may not think a lumbering 7-foot center has anything to do with reducing opponent threes, but the Bucks have only been able to carry out their new directive - which involves off-ball defenders staying stapled to spot-up shooters rather than aggressively tagging or pinching in from the wings and the corners - because they trust Lopez (and Antetokounmpo) to man the back line with minimal reinforcement.

The philosophical shift is also a show of faith in the team's rugged perimeter defenders - Jrue Holiday, first and foremost, but also Wesley Matthews and Jevon Carter - staying attached to ball-handlers while fighting through screens, and pushing those ball-handlers inside the arc. In short, the Bucks are tasking the defenders involved in a central action to handle things on their own and trying to keep everyone else at home, at least until late in the shot clock. Lopez is playing the same deep drop and one-man zone he's always played in Milwaukee, he's just doing it with a bit less help.

The upshot is that the Bucks are allowing more shots at the rim, but not by much - they still rank fifth in the NBA in suppressing rim volume - and now they rank second in limiting 3-point attempts and first in limiting corner threes, according to Cleaning the Glass. Crucially, all of the opponent triples they've cut out are of the catch-and-shoot variety. Last season, half of the shots they conceded came after zero dribbles, but that's down to a league-low 36.8% this season, per NBA Advanced Stats. You can see what kind of shots they're comfortable giving up.

That scheme still has its limitations, especially against superstar creators who can score at all three levels and have no issue dribbling themselves into high-value looks. Trae Young carved Milwaukee up for 42 points last week in a game that demonstrated the precarity of the help-averse approach.

Here, for instance, Holiday overplayed Young's right hand and essentially chaperoned him into the lane going left. Jordan Nwora was on the strong-side wing guarding a moderately threatening shooter in De'Andre Hunter and offered not so much as a stunt to try and deter Young's progress or force him to give up the ball. It was entirely up to Lopez to impact the drive from the baseline, and doing so required perfect timing so as not to give up the easy drop-off to Onyeka Okongwu. A fraction of a second late, and it was an easy layup:

But the Bucks are clearly confident that their gambit will pay off more often than not, and so far they've been proven extremely correct. Lopez is contesting 8.1 field-goal attempts at the rim per game (significantly more than in any other season of his career, and more than anyone other than Nikola Jokic this year), and he's limiting opponents to a paltry 52.6% conversion rate on those shots, according to NBA Advanced Stats. For comparison, Milwaukee's at-rim defensive field-goal percentage when he's on the bench is 66.6%, per Cleaning the Glass.

Another way Lopez is able to take pressure off of the defenders around him is by negating the need to double the post. His combination of size, strength, footwork, and anticipation makes him uniquely equipped to handle the back-to-the-basket bruisers of the world. As rare as those are in this day and age, at least one of them could be a roadblock to the Bucks in the Eastern Conference. That said, Lopez put Joel Embiid in shackles basically by himself in Milwaukee's season opener.

Embiid clearly wasn't operating at the peak of his powers, but even in his diminished state early this season, every other defense he's seen has sent aggressive help his way - swarming him with swipes and dig-downs and blind double teams. The Bucks threw the odd soft double his way but mostly just guarded him in single coverage with Lopez, who limited the reigning scoring champ to 6-of-21 shooting with just three free-throw attempts and more turnovers than assists.

The lack of extra attention coming down from the perimeter meant the Sixers could only find their way to 24 3-point attempts, and despite James Harden popping off from mid-range, the Bucks squeaked out a win by holding Philly to 88 points.

There are plenty of places to assign credit for Milwaukee's great start and enduring success, starting with Antetokounmpo, the best player in basketball. Holiday remains one of the league's preeminent point-of-attack stoppers, and he's filled in admirably for Middleton as a lead ball-handler. Bobby Portis rains hellfire on opposing bench units. Budenholzer continues to prove himself as one of the game's elite macro-level tacticians. The whole roster is deserving of praise. Just don't forget to tip your cap to the aging - but still spry - behemoth who's literally at the center of it all.