The Bucks Built The NBA’s Best Defense. Now, Other Teams Are Copying It.

Now that they have Giannis Antetokounmpo under contract through 2026, the Milwaukee Bucks can narrow their focus. With the day-to-day, will-he-stay-or-will-he-go pressure removed, the only thing left to do is turn the championship-level roster into an actual champion.

The Bucks won more regular-season games than any team in the league in each of the past two seasons, but they ultimately found themselves on the losing end of a playoff series against the eventual Eastern Conference champions in both 2019 (the Toronto Raptors) and 2020 (the Miami Heat). The Bucks lost those two series for myriad reasons, including Mike Budenholzer’s minutes management, Eric Bledsoe’s seemingly annual playoff disappearing act, Giannis’s free-throw shooting and Giannis’s injury.

Of course, there are also myriad reasons why the Bucks wound up playing in such important playoff series in the first place: Antetokounmpo’s all-around brilliance and Khris Middleton’s outlier shooting, their super-charged offense¹ and their stifling defense. Milwaukee actually led the NBA in defensive efficiency during both the 2018-19 and 2019-20 seasons, meaning the Bucks are trying to do something this season that has only been done three other times since the ABA-NBA merger in 1976:² finish three consecutive seasons with the best defense in the league.

It might be a bit more difficult this time around — not just because it’s rarely ever been done, and not just because of the personnel changes the Bucks made this past offseason, which included bringing in clear defensive minuses like Bobby Portis and D.J. Augustin to play sizable roles that used to be filled by quality defenders like Robin Lopez and George Hill. It’s also because teams decided they should start playing defense like the Bucks.

This is similar to how teams observed Daryl Morey’s Rockets teams taking the analytics revolution to new heights offensively, then spent much of the last decade catching up to Houston by playing Moreyball. The Rockets prioritized two types of shots above all others: threes and layups. Those are the most efficient shots on the floor, so now, teams almost exclusively take those types of shots.

Milwaukee’s defense is very much based on those same Moreyball principles. Budenholzer’s Bucks decided that while opposing teams might want threes and layups, the Milwaukee defense was only willing to concede threes. They protect the paint at absolutely all costs, both with a conservative, drop-heavy pick-and-roll defensive scheme and by weaponizing the help defense instincts of Antetokounmpo and Brook Lopez, turning the duo into the NBA’s version of the Legion of Boom. The Legion of Loom, if you will.

Antetokounmpo and Lopez are arguably the best two back-line helpers in the entire league, with Giannis ranking first in each of the past two seasons in points allowed per possession when acting as the help defender against an opponent drive, per Second Spectrum,³ and Lopez checking in at eighth (2019-20) and ninth (2018-19) while ranking second (2019-20) and first (2018-19) in drive-helps per 100 possessions. The Bucks’ bet has been that having those two players help so aggressively results in the near-excision of at-rim attempts from the opponent’s shot diet, counteracting Milwaukee’s willingness to let opponents launch away from beyond the arc.

For the most part, the gambit has been extremely successful. The NBA began tracking shot location data during the 1996-97 season. From that season through the 2019-20 campaign, no team’s opponents ever attempted a smaller share of their shots from within 3 feet of the basket than opponents of last year’s Bucks, who took only 22.1 percent of their shots in that range, per Basketball-Reference.com.

Meanwhile, only two teams (the 2019-20 Raptors and Heat) ever allowed their opponents to take a greater share of their shots from 3-point range than did last year’s Bucks; and before last season, no team’s opponents had attempted a greater share of their shots from deep than those of the 2018-19 Bucks.

As a result, the 2018-19 and 2019-20 Bucks lured their opponents into shots that originated farther away from the rim, on average, than any other teams during the shot-location-tracking era.

Shots taken closer to the basket are more likely to go in than those that come from farther away; teams that venture deep into the paint are far more likely to draw fouls than those that don’t; and the significant majority of rebounds are grabbed close to the basket. So yielding almost exclusively deep shots actually had a triple-benefit for the most recent two Bucks teams: Not only did it drive opponent shooting percentage down, it also kept the Bucks from sending their opponents to the free-throw line⁴ or allowing offensive rebounds.⁵

What does all this have to do with why it might be more difficult for the Bucks to repeat as defensive-efficiency leaders this year? Well, again, other teams have learned from their example.

On a recent podcast featuring FiveThirtyEight’s own Chris Herring, ESPN’s Zach Lowe made note of how both Van Gundy brothers had repeatedly praised Milwaukee’s defense when appearing on Lowe’s podcast over the past two years. Stan, at least, appears to have taken a cue from them when building his New Orleans Pelicans defense.

It’s early in the season, of course, but the Pellies are one of two teams (along with the Miami Heat) whose opponents’ average shot has originated farther from the basket this season⁶ than the average shot by Bucks opponents in each of the past two seasons, per Basketball-Reference.com. And their opponents have taken just 22.8 percent of their shots from inside 3 feet — not far off from last year’s Bucks’ mark of 22.1 percent. (This year’s Bucks, naturally, are beating last year’s record.)

Teams like the Pelicans and Orlando Magic also now rival the Bucks when it comes to both how rarely they send their opponents to the free-throw line and how often (as a share of missed shots) they grab defensive rebounds — areas in which very few teams truly challenged the Bucks over the past two years.

Of course, the Bucks’ title hopes do not rest on whether they finish the regular season with the NBA’s best defense for the third consecutive year. But the fact that more and more opposing teams seem to be emulating Milwaukee’s defensive priorities actually underscores the need for the Bucks’ own offense to evolve.

In their losses to both the Raptors and Heat, the Bucks’ opponents did the same thing to the Bucks that Milwaukee has so often done to its opponents: wall off the paint and let them fire away. The Bucks tried to take a battering ram to the wall their opponents built around the basket in those two series, only to end up settling for a catapult instead. It didn’t work in the slightest. Milwaukee shot 31 percent from deep in the loss to Toronto and 33 percent outside the arc in the loss to Miami, underscoring how that style of defense works at its best. If they’re going to actualize their championship hopes this season, the Bucks will have to solve opposing defenses, starting with their own.