What’s wrong with the Golden State Warriors’ defense?

The Warriors defense has been the driving force in their rough start and inexperience could be a compounding factor all season long.

Throughout their run to five straight NBA Finals, most of the attention lavished on the Golden State Warriors was concentrated on the sheer magnitude of their star power, and how difficult it was to stop them from scoring because of it.

They had Stephen Curry, the greatest shooter in NBA history. And they had Klay Thompson, the second-greatest shooter in NBA history. And they had Draymond Green, one of the best and most unique playmakers in the NBA. In the beginning, they had a stockade of shooters and screeners, and in the latter portion of that five-season run, they had Kevin Freaking Durant. You could not stop them. In each of the latter four seasons of their mini-dynasty, the Warriors had a top-35 all-time offense, with three units in the top-20 and two of the three most efficient offenses in NBA history.

It’s not that the team’s defense got no attention during this run; everybody knows how much Golden State’s ability to go small and switch across all five positions confounded opposing offenses — especially in the playoffs. But it always seemed secondary.

That’s not the case this season, but that’s also not a good thing. The Warriors had one of the six best defenses in the NBA in each of the first three seasons of their run. The led the whole league in defensive efficiency during their first championship season, then ranked sixth in 2015-16, when they won 73 games behind an offense that was impossibly good. After losing in the Finals they ramped the defense back up again in Durant’s first year with the team, finishing second in the NBA. And then they hit cruise control in the following two regular seasons, only really ratcheting things up when they got to the important games. Still, they managed to finish with units just outside the top-10.

Go take a look at any NBA stats page this morning and see where you can find the Warriors among the defensive efficiency rankings. It might take you a while if you simply scan the team names from top to bottom, because they are dead last, and by a not-insignificant margin. If their 119.1 points per 100 possessions allowed at Basketball-Reference holds throughout the remainder of the season, they’d actually become the worst defense in NBA history, overtaking last season’s LeBron James-less Cleveland Cavaliers.

And in some ways that’s poetic. The Cavs lost the heart of their championship-contending teams, and the result was a young squad that couldn’t stop anybody. The Warriors still have Steph and Draymond, but KD is in Brooklyn, Klay is probably out for the year, Andre Iguodala is waiting for the Grizzlies to waive him, Shaun Livingston is retired, and all of the various centers they ran through over the years have moved on.

What’s left is a roster absolutely stacked with young players who probably do not really know what they are doing yet defensively. As Steve Kerr mentioned before the start of the season, the Warriors now employ nine players aged 23 or younger. Seven of those nine players are receiving double-digit minutes per game three games into the year. The only players 24 or older in the rotation are Green and Curry (not a strong defender), plus Damion Lee (same) and Glenn Robinson III (also).

As a result, the Warriors have gone from routinely being one of the most experienced teams in the league to being one of the least. Golden State carries a minutes-weighted age of 24.8 years old so far this season, per Basketball-Reference. That makes the Dubs the seventh-youngest team in the NBA. How does that compare to previous years?

Given the strong negative correlation between youth and defense, it should not be all that surprising that the Warriors are struggling to get stops — especially early in the season. It’s unlikely they’ll end of being the worst defense in NBA history, sure, but barring a roster change or sudden emergence of multiple quality defenders from among the youngins, a yearlong inability to prevent opponents from putting the ball in the hoop is likely to hold them back from reaching their goals.