The final frontier: Have the Rockets hit the limits of an offense-first game?

The Houston Rockets of the James Harden era haven't just been emblematic of what you might call the "modern NBA." To an extent, they're the reason it exists in its current stylistic form.

The Rockets helped mathematize the game, bringing the tenets of Moreyball - the idealized shot profile preached by their data-obsessed general manager Daryl Morey - to the mainstream. They pushed the 3-point revolution past what once seemed like its logical or conceivable endpoint, and other teams had no choice but to follow their lead. By bringing a set of analytic principles to life, the Rockets fundamentally changed the way NBA basketball is played.

The upshot of that revolution is that a higher premium is placed on offense than defense, with the former often coming at the expense of the latter. That tradeoff has worked for the Rockets, to a point. Since Mike D'Antoni took over as head coach and jolted their offensive system into overdrive, they've won exactly 70% of their games - second in the league to the Warriors during that span.

But while D'Antoni brought the process to completion, the Rockets set themselves on this path the moment they traded for Harden. All teams are beholden to their stars, and building a roster around a minus defender who also happens to be one of the greatest offensive players of all time will inevitably tilt a team's priorities. Ideally, you can paper over your star's weaknesses by surrounding him with players who do the things he doesn't. But you also want to surround him with players who amplify his strengths, and sometimes it's hard to find both.

One side of the ball hasn't always come at the cost of the other for the Rockets; they ranked seventh in defensive efficiency in 2017-18, and their playoff defense showed stretches of real brilliance in each of the last two springs. But it's always been clear where this team butters its bread, even if it's never been quite so evident.

This year's Rockets, having replaced Chris Paul with Russell Westbrook and cut bait with acclaimed defensive coordinator Jeff Bzdelik, seem built to test the limits of a defense-for-offense compromise. What clearer manifestation of that bargain could there be than a game they somehow won despite surrendering 158 points in regulation to the Washington Wizards?

The front office had justifiable reasons for choosing to move Paul for Westbrook this past summer, from Westbrook's comparative youth and durability to the happiness of Harden - who'd reportedly grown disillusioned with Paul as a player and teammate. But Morey has made it plain that, above all, he expected Westbrook to make the Rockets a better offensive team, going so far as to suggest that this year's outfit could be the most efficient offense in league history (not much of a leap from where they've been the last two years, but still). The unspoken part of Morey's optimistic assessment was that Westbrook likely wouldn't help Houston's defense, which already slipped to 17th in efficiency a season ago.

What made Paul's stint with the Rockets so successful was that he provided the best of both worlds. He helped Harden orchestrate their deadly spread offense, while also propping up the team's defense; he could help and recover, switch, deny penetration, and force turnovers without making costly mistakes. The Rockets were 7.7 points per 100 possessions stingier defensively with Paul on the floor last year. Whatever interpersonal disharmony he may have helped cause, he provided a semblance of two-way balance the team otherwise lacked.

Without Paul's thumb on the scale, Houston's been a defensive featherweight in the first two weeks of this season. The Rockets are 4-3 against a soft schedule, own the league's 28th-ranked defense, and have surrendered 13.1 more points per 100 possessions with Westbrook on the floor than with him on the bench. He and Harden in tandem have played to a minus-5.9 net rating so far.

Westbrook's biggest issue, as ever, is that he plays off-ball defense much like he plays off-ball offense: hands on his knees, rooted in place, unconcerned with the play when it doesn't directly involve him. When he's responsible for making the weak-side rotation to tag the roll man, he tends to either arrive too late or simply get out of the way upon arrival. It's part of the reason the Rockets have been the worst team in the league at defending the roll man in the pick-and-roll, according to NBA.com.

When he isn't ball-watching or zoning out, he makes needless gambles that crack open canyons of space behind him.

The issues go far beyond Westbrook. The Rockets as a team have been embarrassingly bad at defending in transition, giving up 1.41 points per possession - worse than any team save the Hornets, according to Cleaning the Glass. In theory, that's just a matter of effort. But it's a particularly big challenge for the Rockets because they shoot a ton of threes. That means they miss a lot of shots, which gives opponents more opportunities to run off of defensive rebounds. It's a textbook example of a basketball feedback loop.

They've scarcely been better at defending in the half court, where they've been shredded by backdoor cuts thanks to a combination of inattentiveness and minimal back-line help. They're also quite susceptible to slipped screens. Harden, Westbrook, Tucker, Danuel House, and Eric Gordon (off to a miserable start) have all been repeat offenders.

The defense as a whole has been plagued by lazy and easily conceded switches that offer no resistance or physicality on the exchange. Two years ago, their system worked because they switched swiftly and physically enough to plug gaps, and because Harden competed and there weren't any obvious places to attack. Now there are soft spots aplenty. Tucker has historically done herculean work covering for his teammates, but in his age-35 season, he's slipping.

Switching can help minimize a defense's movement and exertion, while nudging an opposing offense out of its comfort zone. But if overdone, or simply done for its own sake, it can engender malaise that bleeds into other habits. You see it manifest for the Rockets in guys lunging or reaching instead of moving their feet on the perimeter, expecting that somebody else will clean up behind them. You see a lot of pointing for this guy or that guy to handle this switch or make that rotation, which triggers breakdowns that lead to open threes.

Here are Chris Clemons and Tucker miscommunicating on a switch:

Here's Harden imploring Thabo Sefolosha to go help at the nail, and in the process neglecting his own rotation:

You'd expect that kind of discombobulation to get cleaned up as the season goes along. And other things will stabilize, like opponents shooting 42.3% on above-the-break threes. But some of these issues are more deeply embedded. Westbrook and Harden won't suddenly expunge bad habits they've exhibited for a decade. The Rockets can't escape their alarming lack of defensive talent on the perimeter. And they'll eventually need to contest or deter those attempts from beyond the arc - which they're allowing in abundance - if they want their 3-point defense to meaningfully improve.

They can take some small solace in the fact that last year's Rockets had a similarly vexing start, their struggles lasting well into December before they pulled things together and finished the season like a house afire. But on paper, this year's model is a worse defensive team.

"We need to get better," Morey told Chris Mannix of Sports Illustrated this week. "No one is hiding from that."

Morey added, "I'm very confident that we have the right players and coaching staff, and that we have the defense. I know that sounds crazy. I know I have said stuff like this in the past. We just have to have the right execution. (Seven) games in, we have played a mix of teams. Our shot-making has made us look worse than we are. Maybe (after) 20 games, if we are still struggling, then we’ll have to take a look at things."

What would "looking at things" look like? Can Morey do anything on the trade or the buyout market that moves the needle? It isn't an accident that he pointed to the 20-game mark, which will arrive just before the date (Dec. 15) on which players who signed new contracts in the offseason become eligible to be traded.

Nabbing Andre Iguodala would go a long way, to be sure. But barring that, the trade route doesn't present many obvious options, because the Rockets' asset cupboard is bare. They already sent out two future first-round picks and swap rights on another two in the Paul-Westbrook trade. Who on the team qualifies as a trade chip? Clint Capela's stock isn't exactly soaring, and Gordon's might be tanking.

Unless or until Morey manages to pull off a roster upgrade, the Rockets' success or failure will hinge on whether they can pile up enough points to outrun their defensive demons. Some nights, that might mean dropping 159.

This may not be new - the Rockets have been going all-in on offense for years - but early indications suggest the franchise that helped perfect that approach is finally confronting its limits.

Joe Wolfond writes about basketball and tennis for theScore.