What changes can we expect from the Houston Rockets' next coach?
After the Los Angeles Lakers eliminated the Rockets in the second round of the playoffs, Mike D'Antoni, whose four-year contract had expired, informed the franchise that he would not return as coach, according to a report by ESPN's Adrian Wojnarowski.
Whoever replaces D'Antoni will have to work with the Rockets' unique roster and the particular ways that James Harden's and Russell Westbrook's skills shape Houston's approach on both ends.
Let's take a look at the options for the Rockets' head coach of the future.
D'Antoni adapted offense to suit Harden, Westbrook
There was a sad twist in the way Houston struggled to combat the airtight defense of Oklahoma City Thunder rookie Luguentz Dort on former MVP James Harden during the first round of the playoffs. The natural solution would be to create space for Harden via on-ball screens, but that's no longer something the Rockets can capably do.
The twist, naturally, is that D'Antoni is as responsible as any individual for the rise of ball-screen offense over the past decade and a half. During his time as head coach of the Phoenix Suns, D'Antoni unleashed spread pick-and-roll concepts that were common in Europe -- where he'd played and coached before returning to the NBA -- on an unsuspecting league. With the help of a perfect pick-and-roll duo in Steve Nash and Amar'e Stoudemire, D'Antoni more or less designed modern NBA offense.
At times derided in the past for relying too heavily on the pick-and-roll, D'Antoni started out largely playing that way when he was hired in Houston in 2016. The following season, James Harden ran more ball screens (4,022) than any other player in the NBA, per Second Spectrum tracking, and the Rockets increased their pick-and-roll usage with the addition of maestro Chris Paul in 2017-18.
As Harden's game evolved, however, D'Antoni adapted with it. Increasingly, Houston began relying on Harden isolations, which made it more difficult for defenses to trap the ball out of his hands and played more to his growing strength shooting step-back 3-pointers.
That evolution reached another phase this season, with Westbrook replacing Paul at point guard. Because of Westbrook's poor outside shooting, opponents found it easier to crowd the paint against pick-and-rolls involving Harden and center Clint Capela, a dangerous lob threat in the vein of Stoudemire. D'Antoni's solution, discovered while Capela was injured, was to play without a traditional center -- swapping a pick-and-roll finisher for additional spacing on isolations.
After P.J. Tucker moved to center in place of Capela, the Rockets ran nearly six fewer ball screens per game than any other NBA team. While that rate increased in the postseason, Houston was still ill-equipped to deal with Dort, whose relentless defensive effort made isolations difficult for Harden. Since Tucker is not a threat rolling to the basket, his screens posed little threat to the Oklahoma City defense.
Given the personnel in place -- and likely to return, as the Rockets have limited flexibility to reshape their roster during the offseason -- it's unclear how much differently they could operate next season. Generating more early opportunities might help unstick the offense, which ranked 13th in the league with 8.4 fast-break points per game in the playoffs, according to NBA Advanced Stats. But again, it will be hard to find a coach more qualified to teach the transition game than D'Antoni, who was practically synonymous with up-tempo offense during his Phoenix tenure.
Switching defense built around Harden's limitations
Ordinarily, the law of NBA coaching changes would suggest that an offensive-minded coach like D'Antoni must inevitably be followed by one who is more focused on the defensive end of the court. There too, whoever replaces him will run up against the limitations of the Houston roster.
Before joining the Rockets, D'Antoni had generally favored conservative defensive schemes that stayed home on 3-point shooters at the expense of protecting the rim. That style changed in Houston, where Second Spectrum data shows nobody switched against more ball screens over the past four seasons than the Rockets, who did so about 38% of the time during the regular season.
A switch-heavy defense plays to Harden's defensive strengths and minimizes his weaknesses. Because of his physical strength, he's an excellent post defender against bigger opponents, but he struggles badly when asked to defend in space. Houston's move to play without a center was only the latest and most dramatic step in building a roster designed to switch. The 6-foot-5 Tucker can capably defend smaller players on the perimeter, while the Rockets' other perimeter players (notably Westbrook, Eric Gordon and Danuel House Jr.) play bigger than their size.
Certainly, we've seen evidence of how well a switching defense can work for Houston. That defense was a big factor in the Rockets' 2018 run within a game of the NBA Finals, and as recently as the opening round of this year's playoffs, Houston held Oklahoma City to the league's lowest postseason offensive rating.
When the Rockets' defense broke down in the second round against the Los Angeles Lakers, who posted the best offensive rating among teams in the conference semifinals, lack of size was a primary culprit. The Lakers made an incredible 20.4 shots per game in the restricted area, per NBA Advanced Stats, more than four better than any other team in the round. And their 29% offensive rebound rate was also tops in the league.
Again, transition looms as a source of potential improvement for Houston. Their transition defense was trampled by the Lakers, who averaged 16.8 fast-break points per game -- yet again best among teams in the conference semifinals.
Undoubtedly, getting back on defense will be a focus for the Rockets' next coach -- whether it's Sam Cassell or another candidate -- but it's worth noting this issue predates D'Antoni's arrival in Houston. The Rockets ranked 27th in terms of points lost per possession in transition in 2015-16 under Kevin McHale and J.B. Bickerstaff, per Cleaning the Glass, and haven't rated better than league average in this category since acquiring Harden in 2012.
Houston's next head coach will find ways to put a stamp on the team next season. Still, given how dramatically D'Antoni had to adjust his philosophy to fit the talent he was given, further drastic changes seem unlikely. Whether the Rockets can go deeper in the playoffs next season will likely have more to do with whether Russell Westbrook enjoys better health and if Daryl Morey can unearth more bargain finds to fill out the rotation than whoever is on the sidelines.