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SAN ANTONIO — Not long after Mike D'Antoni was introduced as head coach of the Houston Rockets late last May, the NBA's leading advocate of fast-paced basketball reached out to James Harden.

How did that conversation go? We have to fast-forward.

In an essay published at the Players' Tribune a few hours before the Rockets crushed the San Antonio Spurs on Monday, 126-99, in Game 1 of their Western Conference semifinals series, Harden described how a series of conversations with D'Antoni last summer had generated what he called his new obsession, a devotion to being "the kind of leader who does what's necessary to win."

On Tuesday morning, I asked Harden one simple question about the talks he referenced in his piece: "During all those talks, did Coach D'Antoni mention defense, even once?"

Harden smiled, shook his head, and said, "No."

Then he walked straight to Rockets assistant coach Jeff Bzdelik, the defensive coordinator D'Antoni hired a few days after he accepted the Houston job.

"Ask me if Coach (Bzdelik) talked to me about defense," Harden said.

The answer was obvious, especially with the 64-year-old Bzdelik nodding his head.

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D'Antoni freely admits Bzdelik has complete command of the Rockets when their opponent has the ball, and Rockets fans are accustomed to seeing him up on the sidelines, signaling defensive changes and giving defensive instructions during timeouts.

D'Antoni got to know Bzdelik during the four seasons the latter spent as head coach at Wake Forest, where D'Antoni's son, Michael, will graduate in a few weeks.

"During that time [Michael] was there, I'd sit and talk and chat with Jeff and his coaches and developed a relationship," D'Antoni said. "I hadn't really known him before. It's been a natural fit, and we were lucky to get him. He's unbelievably good with our defense."

Bzdelik spent 18 years on NBA benches and another nine as a college head coach at Air Force Academy, University of Colorado and Wake Forest before joining D'Antoni in Houston. His first assistant coaching job in the NBA was for six seasons under defensive-minded Washington Bullets coach Wes Unseld. From there, he became a scout for another defensive stickler, New York Knicks coach Pat Riley.

In 1995, he followed Riley to the Miami Heat, where he served another six seasons as an assistant coach. Eventually, he landed an NBA head coaching job, taking over the Denver Nuggets in 2002-03 and forging a turnaround from 17 wins in his first season to 43, and a playoff berth, in 2003-04.

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D'Antoni and Bzdelik liked the Rockets roster they inherited and heartily endorsed general manager Daryl Morey's player additions. They also knew Houston would have to improve at the defensive end if the Rockets were to enhance their prospects for playoff success.

"We knew we were going to score a lot of points, so our whole focus was if we could just get in the top 10, top 15 defensively we could have a really special year," D'Antoni said. "That was our focus, from July on. Then, just put a system in place. But, it always comes down to the players. They've been good and resilient and gotten better all the time.

"Jeff has kept it simple and gotten them to have good habits—stayed on them, stayed on them and stayed on them. Now, it's ingrained. Jeff did an unbelievable job, and the players have been terrific."

The Rockets weren't devoid of defenders when D'Antoni and Bzdelik arrived. Rather, they were in need of proper focus.

"I believe [guard] Pat Beverley is one of best defenders of point guards in the league and Clint Capela and Nene do a really good job at center," D'Antoni said. "Of course, Trevor [Ariza] always takes the hard assignment, the superstar assignment, and always does a good job with that. Then, it's just pressure on the ball and guarding the rim."

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The Rockets have made a tweak or two to their defensive scheme for the playoffs, but they dominated the Spurs on Monday with the same scheme they had used in four regular-season games. The game plan included sending a double-team from the baseline whenever LaMarcus Aldridge got the ball in the low post. Aldridge completed a night of total frustration with only four points, his least productive playoff game since joining the Spurs for the 2015-16 season.

"They were baseline double-teaming me, so I was trying to read it," Aldridge said. "And, they bluffed me about two or three times to pass it, and they didn't double. But they doubled three or four times, too."

The result made even Ryan Anderson look a little like Draymond Green, which may qualify Bzdelik for some sort of genius grant.

"We have a team defense," Anderson said. "We need to lock in together. That's been a key for us this season, building on playing 48 minutes, playing a complete game. A lot of that is helping each other, having each other's backs. It's not an individual, one-on-one defense we have."

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Houston isn't apt to befuddle the Spurs offense to the extent it did Monday, when San Antonio shot just 31.9 percent in a first half that ended with the Rockets ahead, 69-39. It also shot 36.9 percent for the contest. But, Monday's Game 1 showed that Houston is capable of approximating the kind of defense that produces postseason victories, rather than simply relying on outshooting its opponents.

"We had an honest conversation with everybody on day one," said Bzdelik. "Simply, that if we're going to aspire to be an elite team, then we need to be not only a top-10 offensive team, but a top-10 defensive team. Otherwise, we're kidding ourselves, because history has shown that you have to be elite in both areas. So, we have a bunch of competitive guys who know we've got to do that.

The Rockets fell short of top-10 status in the regular season. They were 17th in the NBA in defensive efficiency, allowing 106.4 points per 100 possessions, per ESPN's Hollinger stats. They know that is not good enough if they want to go deep into the postseason.

"They understand the urgency that if we don't [lock in], our season is over," Bzdelik said. "All year long we have stressed that our habits must be where they need to be because you can't just turn it on and turn it off. You rely on habit; you are creatures of habit. So, that's been the battle."

Thus far this postseason, Bzdelik has been winning the battle. After Monday's game, the Rockets ranked fourth among all playoff teams in defensive efficiency, allowing just 102.8 points per 100 possessions. The Spurs rank 11 th , with a defensive efficiency of 109.1, per ESPN.com.

Besides, D'Antoni prefers the simplest of analytics.

"I don't believe it's asking too much for guys on a fast-paced team to also defend," the Rockets coach said. "Most of it comes from guys buying in and having good chemistry among the team. Then, you may not be the greatest defensive team, but you're going to win a lot of games. Other teams are going to score, but point differential is what we look at. It's a little different rating scale, but, at the end of the day you're just trying to win as many games as you can win."

That plays straight into Harden's new obsession to be the kind of leader who does whatever it takes to win, so when Bzdelik spoke to him about defending, his message was clear.

"I just said, 'Look, do you just want to be a great player, or do you want to be a true Hall of Fame player?' Bzdelik said. "That was all I had to say."

All quotes obtained firsthand, unless otherwise noted. Statistics courtesy of NBA.com unless otherwise noted.