Tonight in Oakland, the Golden State Warriors will face off with the Memphis Grizzlies in a matchup of two of the best defensive teams in the NBA. Seriously, it’s true. Golden State really has one of the best defenses in the league. The Warriors do; with Zaza Pachulia protecting their rim. The Dubs, with Stephen Curry bumbling around every high pick-and-roll. These guys? Yes, those guys are giving up the fewest points per 100 possessions and allowing the second-lowest effective field goal percentage in the league. How the heck are they doing it?

With due respect to Harrison Barnes, the Warriors decision to swap him out for Kevin Durant at the small forward spot this summer was a no-brainer. But, to carve out space for Durant and his big salary, the Warriors were forced to part ways with Andrew Bogut and Festus Ezeli, two of last season’s top-10 rim protectors. Amidst the hubbub of the resulting super-team hot takes, the biggest concern for Warriors fans — and the greatest hope for Warriors haters — was Golden State’s sudden lack of frontcourt depth and how it might impact the team’s defense.

How would the Warriors replace Bogut’s rude presence in the paint? Would Curry’s defensive limitations be exposed this season without a 7-foot-long, Bogut-shaped security blanket there to cover them up? The rumblings grew when the Warriors were forced to scrounge the free-agent scrap heap for the unpredictable JaVale McGee; pairing him with the ground-bound Pachulia, the injured rookie Damian Jones, and the not-very-good-at-basketball Anderson Varejao as their only options in the center.

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The defensive experiment got off to a halting start when the San Antonio Spurs moseyed into Oracle Arena on opening night and promptly fired off 129 points. Pachulia looked overwhelmed by Pau Gasol and LaMarcus Aldridge, and he seemed to be a step slow on all his defensive rotations. The other Warriors weren’t much better, as the new teammates failed to communicate with each other, resulting in several open looks for the Spurs on busted switches of defensive assignments. Consequently, the Warriors opened the season as the worst-ranked defense in the league (131.2 points allowed per 100 possessions). The highly anticipated new-death lineup of Durant, Curry, Klay Thompson, Andre Iguodala, and Draymond Green was particularly ghastly on the defensive end, coughing up 28 points in 9 minutes (140.0 points allowed per 100 possessions).

However, since that embarrassing shellacking, the Warriors defensive rating has been steadily improving and the death lineup has really rounded into form. Now, less than halfway through the 2016-17 season, the Warriors seem to have cemented a new defensive identity.

Trend in defensive rating for the 2016-17 Golden State Warriors compared to other NBA teams, by game (thru 12-31-16)



During the previous two seasons, the Warriors used two different — but both very effective — defensive strategies: one, a scheme that ran shooters off of the 3-point line and funneled ball handlers toward Bogut in the paint, and the other, a small-ball scheme that switched almost every pick-and-roll and relied on long arms and quick feet to wreck havoc in the passing lanes. If Bogut and the starting lineup were the Warriors’ base defense, Iguodala and the death lineup were the blitzing defense that Ron Adams dialed up when the team needed a stop.

Both lineups worked — keeping opponents below 99 points per 100 possessions and under 50 percent true shooting — but by very different means. When Bogut was on the court, the Warriors protected the restricted area exceptionally well, allowing a shot attempt from within three feet only about a quarter of the time (26.2 percent of all field goal attempts) at a paltry success rate of 55.6 percent.

By contrast, the death lineup (of Curry-Thompson-Iguodala-Green-Harrison Barnes) allowed more shots near the rim (30.9 percent from 0-3 feet) at a higher rate of success (59.8 percent). Along the same lines, the Bogut lineups produced more blocks (6.6 per 100 possessions) than the death lineup (4.9 blocks per 100 possessions). However, what the death lineup lacked in rim protection, it made up for with activity, generating more steals (8.8 per 100 possessions) than the Bogut lineups (7.6 per 100 possessions). In particular, Green underwent a Scott Howard-like transformation in the small-ball lineup; scrambling around as an undersized center and bumping up his steals (3.4 per 100 possessions) and blocks (2.5 per 100 possessions), but also his fouls (7.1 per 100 possessions).

Defensive statistics for the Golden State Warriors during the past two-and-half regular seasons, by lineup

This season, the Warriors have basically abandoned their base defense in favor of their blitzing one. With Pachulia in Bogut’s place as the starting center, Golden State can no longer rely on conventional rim protection. They are blocking only 5.2 shots per 100 possessions and giving up a relatively generous field goal percentage in the restricted area (62.2) with Pachulia on the court. Just as they had done in previous seasons, though, the Warriors are making up for their rim protecting deficiencies with more steals, generating 10.1 thefts per 100 possessions!

The defense of the new death lineup — with the addition of Durant and his 7-foot-5 wingspan — is looking every bit as devastating as the previous iteration. Durant, Curry, Thompson, Iguodala, and Green are keeping opponents under 99 points per 100 possessions with a true shooting percentage lower than the original death lineup (47.2). The steal rate is still high (8.8 per 100 possessions) but, in this lineup, Durant’s addition has unexpectedly bolstered the block rate too (10.5 per 100 possessions) and dropped the opponent’s field goal percentage in the restricted area below the mark set by the Bogut-anchored lines (53.5). Durant has been a menace around the rim for the Warriors, averaging career-highs in blocks (1.6) and rebounds (8.6) per game. He’s proving that the glimpses of excellent defensive prowess he displayed with the Oklahoma City Thunder during the 2016 Playoffs can be sustainable when he plays at the power forward position.

Of course, Green remains the key to the Warriors small-ball defense. When playing center in the death lineup this season, he’s posting an absurd 4.3 steals and 4.3 blocks per 100 possessions. He’s also earned extra wins for the Warriors by making key individual defensive stops in the waning moments of several close games.

Interestingly, the McGee-centered lineups look pretty similar to the Bogut-centered lineups with respect to the team’s steal and block rates as well as the frequency and efficiency of opponent’s shots within the restricted area. As a legit rim-protecting center, McGee offers the only chance for the Warriors to play a base defense that is more conservative. Like Bogut, McGee also provides some protection against the accumulation of fouls by his teammates, including Green.

As I broke down in detail last month, the Warriors have continued to diminish the role of the traditional center in their lineups this season. Pachulia and McGee are averaging less than 26 minutes per game, combined. Based on the rotation patterns of the past two postseasons, these two will probably play even less by the end of the year. As such, while the Warriors team defensive statistics are impressive, the true barometer for their ultimate success will be the defensive rating of the death lineup. If those five can continue their trajectory towards becoming an even-more-stingy defensive unit, the Warriors will be tough to beat come June.

The data cited above were collected variously from Basketball-Reference, NBAWOWY, and the rolling charts of Nylon Calculus’ Positive Residual.