Gregg Popovich and Brad Stevens ran into history. We knew The Trilogy was coming. LeBron James is going to his seventh(!) consecutive Finals. The Warriors assembled the greatest team ever, on paper at least. The Dubs and Cavs wiped out the field — they have higher playoff net ratings than any team since 1997. There’s nothing their opponents could do to stop them. Popovich and Stevens positioned their squads to give it a go, but resistance proved futile. The Spurs almost took Game 1 against the Warriors. The Celtics stole Game 3 in Cleveland. In the face of two superpowers converging on the Finals, San Antonio and Boston reached their peaks. Along the way in a season that felt predestined from the start of training camp, Popovich remained a stabilizing force, while Stevens continued to lay a Spursian foundation.

“I thought we had a great season. I’m really happy for the group. There’s only one happy team out of 30. At the end of the day, everybody else is sad at some point,” Popovich said one day after his Spurs were swept by the Warriors. “But if you have half a brain, you put things in perspective.” In doing so, you’ll find the Spurs had significant roster turnover for a Popovich team, with seven new players. It was their first year without Tim Duncan’s presence on the floor. Tony Parker and Manu Ginobili didn’t get any younger. Kawhi Leonard spent his first season as the featured scorer. The Spurs still managed 61 wins with a plus-7.9 net rating, and a trip to the Western Conference finals. They had a 100.9 defensive rating, with Pau Gasol and David Lee anchoring the defense. The 2016–17 Spurs reached their peak.

San Antonio made the playoffs for the 20th straight season. They’ve accomplished this because the front office and Pop’s coaching staff has preached sustainability through the value of continuity and character. Superstars fall short of expectations so often across sports — it’s the culture and players around them that enable them to perform at the highest of levels. The culture installed by Popovich persists, even in a post-Duncan world.

The Celtics are building — they hope — a similar foundation. They have a coach in Stevens who shares Popovich’s ability to maximize his roster. It sounds obvious, but a coach can only manage the players he’s given. They can’t worry about what they might do if they had this guy or that guy: they need to make whatever they have work best. Maximizing his roster has always been Stevens’s speciality, going back to his time at Butler, where he led the Bulldogs to back-to-back title games against elite-level opponents. Stevens never reached the mountaintop at Butler, but the same qualities of those Bulldogs teams are found in these Celtics.

Let’s be totally honest here: This year’s Celtics roster is merely adequate. Isaiah Thomas and Al Horford are stars, but beyond that, the players are just fine, or they’re young. There’s talent to be sure, but so much of Boston’s success is usage-based. And yet, the team still won 53 games, and was one of only five teams (along with the Warriors, Spurs, Jazz, and Raptors) to have a top-12 offensive and defensive rating. They also made it to the Eastern Conference finals and won a game even after losing Isaiah. “They had to kind of reshape,” LeBron James said after the Celtics lost IT to injury, “and that’s the beauty of having Brad Stevens as your coach. You’re able to reshape what you do offensively and still be in a good rhythm. It’s been challenging for us … [He’s] been killing us on ATOs and keeping us off balance.”

What LeBron means by “ATOs” is after-timeout plays — when a coach calls a timeout, draws up a play, and then the team executes. Stevens is one of the best in the NBA at them, and it shows in the stats: the Celtics ranked third in points per possession scored off ATOs, per Synergy Sports. “He has so many different wrinkles, misdirection, thinking the ball is going this way, he has a misdirection going the other way,” LeBron said. “You’ve got to kind of keep your head on a swivel. He has a lot of packages. So you can plan for a few, but then he might run something you’ve never seen before.”

Schemes, playbooks, and X’s and O’s all matter in coaching. But what matters most is player development and getting players to commit to getting better every day. “Those character traits are going to be important moving forward,” Stevens said after Game 5, “that they continue to be passed on from the guys in that locker room.” What makes the Spurs the Spurs is that they’ve established an institutional culture that enables them to sustain success, and plug and play new pieces.

The Celtics are still in the process of building their program. They miraculously won Game 3 in Cleveland, but they’ve also suffered setbacks like Game 5, when they came out without any fight from the opening tip. It was a moment very much unlike the rest of their season. Their execution fell apart. The team lacked life. The Celtics didn’t run away, but it’s like they knew they were in for a spanking from LeBron and the Cavs.

Just like San Antonio, Boston reached its peak, too. Both of them lost their star to injury. Both of them made positive strides. Both of them fell short. “It’s a good step forward as a season as a whole,” Stevens said after the Celtics lost Game 5. “I told our guys that we made a lot of great strides, but this pain is part of the path to what we ultimately want to be.”

It remains to be seen how many players on their respective rosters will return, because both teams are at a turning point with big decisions ahead. The Spurs will need to decide how to maneuver this transition phase in the post-Duncan era, while the Celtics have the no. 1 pick and can create cap space to make a run at Gordon Hayward. Whether or not both teams accomplish their offseason goals, they are in good hands with their coaches. Ownership and the front office can feel confident that the talent put out on the floor will at least meet, if not exceed, whatever expectations are set for the team.

It could be a long and winding road for the Spurs and Celtics to ever return to the Finals, but they’ll continue to make incremental progress each year as — they hope — the gap closes on their conference roadblocks. “I don’t have any objectives, other than winning the whole thing,” Stevens said. “That’s the only goal you shoot for. Because then if you don’t, if you put your goals lower, you create a ceiling for your team.”