The Sixers lacked cohesion last year, but that does not sound like it will be a problem in 2019-20 | David Murphy

The walls were talking at the Sixers’ practice facility on Tuesday afternoon. A steady rhythm of squeaking soles and clapping hands pulsed out from the sealed-off gym like a congregation on Sunday morning. The anticipation had been building for weeks as a procession of familiar names and faces arrived and added to the numbers and intensity of the daily pickup runs. Now, after months of talk, the beginning had arrived.

“This is the best first practice I’ve been a part of since I’ve been with the Sixers,” Ben Simmons, starting his fourth training camp, said as he looked out on a court where several groups of teammates were finishing up their shooting drills. “We’re straight to it. We know what we want to do. We know what we’re here to accomplish.”

Whether or not you believe in the Sixers, the Sixers themselves do, and you don’t have to spend much time around them to understand the extent to which that is true. There is a unique energy to this team, a palpable sense that, after a year of roster upheaval, Elton Brand and his front office have finally landed on the optimal configuration of pieces.

It’s an interesting thing to behold, and even more so to contemplate. For a rotation that has added two starters and a handful of bench pieces while parting ways with two of its foremost scorers, the collective agency that its components already project is a testament to the Sixers’ potential. Ownership is a difficult thing to forecast when assembling talent on paper, but this group clearly feels it.

“If you look at our group last year, we came together without a true understanding of how each other plays,” said Tobias Harris, who figures to inherit much of the scoring load that Jimmy Butler carried last year. “So that was a thing these last three weeks that we really wanted to kind of expedite. Kind of just learn each other’s similarities and how we play and operate on a basketball court in a different way.”

It’s difficult to overstate the importance of such a thing, particularly with a roster that features such a counterintuitive mix of talent. With three starters listed at 6-foot-10 or taller and the 6-9 Harris guarding the three, the Sixers will enter the season with one of the NBA’s longest first units in recent memory. In a recent five-on-five run, backup center Kyle O’Quinn marveled at the thicket of bodies and arms present on the court.

“The paint was just clogged,” he said.

At the same time, the presence of Harris and former Celtics center Al Horford in front of Joel Embiid is a bit of a departure from the way the NBA is trending. Harris spent the summer working on his lateral strength and quickness in an effort to improve his defense, and Horford has long been one of the league’s most technically skilled big men. Still, in the Sixers’ Oct. 23 season opener against the Celtics, Harris could find himself matched up against a dynamic slasher in Jayson Tatum while Horford is forced to contend with either Gordon Hayward or Jaylen Brown at the four.

“The fun thing is our defense, we’re all going to have each other’s backs,” Horford said. “That’s the first thing. We all know that we all have the ability to cover individually, but the way we’re going to be special is all of us covering for one another. We’re not going to be afraid if there’s a mistake. We’re going to cover it. And we’re going to be strong and set a tone on the defensive end. And we have guys that want to do that. And as long as everyone is on the same page on the defensive end, we’re going to be trouble.”

The Sixers are counting on that mentality to tip the matchup scales in their favor.

“I can already tell that we’re building camaraderie, and I think our chemistry is going to be good because we have guys who genuinely like each other,” said Josh Richardson, who will be the first line of defense against opponents’ primary ballhandler. “I think we’re going to be a tough team. Just greedy. A guy like me, I can win or I can lose with a team like that. I can sleep at night with a team that I know went out there and got in a fistfight, got in a brawl.”

Along with the attitude, the Sixers will lean on a rebuilt bench that includes a trio of wings in James Ennis, Zhaire Smith and Matisse Thybulle who can sub in for Harris or Horford and create a more traditional lineup.

“The potential is amazing,” Harris said. “And not even necessarily on the basketball floor but as a team off the floor. I know that this is going to be a really good team that’s going to get along with each other. It’s going to be open to helping each other, because we all have one solid goal.”

The staying power of these sorts of positive vibes remains to be seen. But you didn’t need to see their first practice to know that, at least for the moment, they are real.