Is the Rockets’ defense good enough to win a title?

In the absence of an interior anchor or lockdown isolation defender, the Rockets have become the NBA’s peskiest defensive team.

When the Houston Rockets effectively swapped Clint Capela for Robert Covington at the trade deadline, they not only unleashed the most progressive offensive system in NBA history but vastly widened their range of outcomes. For a team like the Rockets, the difference between losing a first-round playoff series and a Game 7 of the Western Conference Finals is negligible; neither scenario ends with them hoisting the Larry O’Brien Trophy. Whatever downside risk came with not playing a big man couldn’t be worse than the floor that previously existed. Houston was a good team before it went small, but likely nothing more than second-round fodder for a legitimate championship contender. It might still be that, but now has the offensive upside to be something much more.

With the added entropy came a wave of questions Houston would have limited time to answer — chief among them whether it could stop opponents enough for a nuclear offense to blast through the postseason. Surrounding James Harden and Russell Westbrook positionally flexible shooters all but guarantees a lethal offense, but it’s unclear whether that’s a workable approach on the other end. That question has yet to be definitively answered, but the Rockets have offered something of a blueprint for how they might get by defensively.

How does the Rockets’ defense work without a traditional center?

In the absence of an interior anchor or lockdown isolation defender, Houston has become the NBA’s peskiest defensive team, getting their hands on the ball and in the passing lanes to force turnovers and make opposing offenses uncomfortable. By digging down on drives, darting through passing lanes, drawing charges, and inviting post-ups, the Rockets have found ways to maximize what little size they put on the court — and even use that lack of size to their advantage. “Our energy and our effort and our aggressiveness defensively is something that we have to hang our hats on, especially being small,” Harden told TNT’s Jared Greenberg after a win over the Lakers.

Through five games in the bubble, it’s Houston’s defense — not its offense — that has propelled it to a 4-1 record. The Rockets’ 107.5 defensive rating places fifth out of 22 teams (compared to a 12th-ranked offense); they lead all teams in deflections and rank third in opponent turnover percentage, which not only compensates for the absence of a rim protector, but helps create quick, easy offense. Nearly 16 percent of Houston’s bubble offense has come in transition — the second-highest mark in the league — and quick pokes at the ball often yield easy buckets on the other end:

Covington and P.J. Tucker, two master thieves and shrewd help defenders, provide the foundation for Houston’s defense, but most every Rocket has found some way to contribute. In a more aggressive scheme, Westbrook’s penchant for gambling in the passing lanes becomes a bit more palatable, and Harden’s hands are one of his few defensive strengths. Another is his physical strength — a shared trait among most of Houston’s rotation. Each of the Rockets’ four opponents in the bubble has tried to exploit Houston’s lack of height by feeding their big men on the block, but none have been able to make those plays worthwhile against sturdy, compact defenders. Watch Harden plant himself to the floor against Kristaps Porzingis’ futile attempts to bully him:

Brook Lopez might have an easier time backing down a brick wall than the immovable Tucker:

Watch enough of these heavyweight bouts and you’ll notice that the Rockets seldom contest these kinds of shots, but rather do their work on the ground (Andre Iguodala pioneered this tactic against LeBron James and Kevin Durant, and many Rockets have adopted it in the years since). Instead of rising up for an improbable block of an already difficult shot, Tucker lowers his center of gravity, denies Lopez a deep catch, absorbs contact with his chest, and swipes at the ball on its way up.

The rest of the NBA targeted Houston in the post more than any other team this season, yet the Rockets hold opponents to the third-lowest post efficiency in the league. No one is more aware of that fact than the Rockets themselves, who gain yet another mathematical edge by inviting basketball’s least profitable play. On the perimeter, they often force low-value isolations by switching ball screens and preventing separation at the point of attack:

Yet there are ways to attack Houston’s undersized defense, provided its foes can resist the antiquated temptation to play through the low block. The Rockets are incredibly vulnerable on the defensive glass, and their all-out devotion to forcing turnovers and taking charges leaves key players in jeopardy of fouling out. Opponents can exploit their switching defense by using Harden’s man as a screener, isolating, and waltzing toward an unprotected rim. Draw a help defender or two, and spot-up 3s materialize. Teams might also be wise to go at the spindly Covington more often, thus exposing his own limitations on the ball and taking away Houston’s best help defender. The Rockets are one of the NBA’s most aggressive help defensive teams, but the lack of resistance they offer at the rim could be a critical weak point against the wrong teams.

Their frantic, high-risk defensive approach only pays off if the Rockets have the firepower to torch opponents on offense, which thus far they haven’t. Houston ranks ninth (out of 22 teams) in points per possession in the bubble after trailing only Dallas during the regular season, which leaves them with only a slight positive scoring margin over four games. Most of that is due to variance in 3-point shooting (which, admittedly, is a high-variance part of the game), and the Rockets should regress back to their devastating levels of offensive efficiency. They’ve created the highest expected shot value in the bubble thus far, taken nearly a fifth of their shots from the corners, and turned the ball over on a minuscule 8.7 percent of their possessions. Harden and Westbrook are taking fewer trips to the foul line, but that’s partly a product of how often they set up open triples for teammates.

Houston’s defense will be tested more intensely as it faces more talented and disciplined offenses with time to scheme for a playoff series. James and Anthony Davis will put more strain on a small frontcourt than perhaps any team the Rockets will see in the playoffs, no one punishes overly aggressive defenses like Nikola Jokić, and the Clippers have the personnel to beat Houston at its own game. Those teams have floated over Houston in the Western Conference hierarchy all season, but if the Rockets are proving anything in the bubble, it’s their capacity to disrupt.