DALLAS — When Al Horford talks about what the playoffs are like, it’s wise to listen. The 38-year-old veteran, who has played in 185 postseason games in his career, uttered the most meaningful observation following the Dallas Mavericks’ drubbing of his Boston Celtics on Friday.

“You know, I’ve been in a lot of these, and usually by the second game you’re making adjustments,” Horford said. “Third game, you’re making another adjustment, and that’s kind of how it is. And for us, we’ve had the first three games, we didn’t really make any adjustments. So today, they did something. We have to see how we can be better and prepare for it.”

In other words, the Mavericks have finally made their opponent think. They’ve finally turned the NBA Finals into an actual series. It’s just unlikely for it to actually matter, given the team falling into a 3-0 deficit that provides zero margin for error.

Dallas, facing elimination, thrashed the Celtics 122-84 in Friday’s Game 4. It was a victory so decisive it can’t entirely be explained by the leading team letting up, but one that still may not matter. The likeliest outcome remains the historical one: no team has ever come back from this series deficit in this league’s history.

But when Dallas almost certainly enters its summer as the losing Finals team, it should feel disappointment it wasn’t able to play like this sooner. Because despite what was said about them, despite the belief shared by some that the Minnesota Timberwolves or Denver Nuggets should have been here instead, despite the disillusionment that Boston exposed the Mavericks in some fundamental way even as they existed as one of the final two teams left standing, there’s no question that the Mavericks were finally themselves on Friday.

They were the team that earned this Finals berth by merit. It just took too long for them to get here.

“We had to play our A game,” Mavericks coach Jason Kidd said. “It was this or we go on vacation.”

At this point in the finals, there’s little doubt which team should be viewed as the better one. It’s the one that won 64 regular season games, cruised through its Eastern Conference opponents, has been here before, and marched to the series lead that sets such a historical precedent. What could have changed that inevitability is Kristaps Porziņģis’ injury, which held him out of Games 3 and 4 without any clear determination when he’ll return. It’s an unfortunate injury, of course, but one that gave Dallas some semblance of a chance. Also, the team lost Game 2 despite Boston’s abnormally poor shooting performance and fell in Game 3 despite long stretches as the dominant team.

Under Kidd, Dallas has often grown into playoff series. There’s a reason that the team is 4-1 in his tenure after losing Game 1. The Mavericks finally found their footing on Friday, regaining the math advantage that has served them so well during this run, which has been points in the paint. Dallas scoring 60 there while Boston managed just 26 can’t fully be explained by adjustments, but it certainly displayed much of this game’s story.

There are some things that may be breakthroughs under any circumstance. Dereck Lively II, the team’s brilliant 20-year-old rookie center, might have simply needed two games to adjust to a Finals appearance he couldn’t have ever expected. His 11-point, 12-rebound double-double reestablished him as the team’s third most-important player, but it took several games to gain that comfort shown all postseason that no one could fault him for lacking at this stage. (He also hit his first career 3-pointer on an open look from the right corner, which makes him the youngest player to hit such a look in the Finals. The last time an NBA player made his first-ever 3 in the Finals was the Lakers’ Josh Powell in 2009.)

Likewise, even though Dallas finally played its best perimeter defense this series, it can’t be overstated how Boston — and Porziņģis’ absence — impacted that. Even after the Mavericks’ trade deadline moves sparked a 32-14 record entering these Finals, Dallas still had struggled against teams that spread the floor with five shooters.

“Obviously, we haven’t really played a lot of five-out teams,” Josh Green told The Athletic. “I think the coaches did a great job making the necessary adjustments that we needed to make, and obviously that paid off tonight. I’m sure we’re going to have more adjustments that we’re going to need to make. I think it’s important for the guys to be happy about this, but know that we need to do more.”

But there are other laments Dallas might take into the offseason, ones that were fixable sooner. The team’s rotation, now solidified around nine players, took three games to form in earnest. While bench guard Dante Exum struggled in this postseason, he was barely used in Game 3 despite suggesting he could provide the shotmaking and pace the offense lacked in Game 2. On Friday, he chipped in 10 points.

Then, there are the superstars, Luka Dončić and Kyrie Irving, who had their own struggles. For Irving, it was the opening two games in Boston, when he all but admitted that the past history with that franchise might have gotten to him. His co-star, on the other hand, was given an even harsher assessment in the national media after the series’ third game, when he continuously complained to the officials and eventually fouled out with about five minutes remaining.

If Dallas had adjusted sooner, if the team’s superstars had been better when needed, if this, if that, if whatever. None of that happened. Even after Friday’s win, Dallas still must win three straight games against a team that has proved its merit. One that has been here before, that has already learned the hard lessons the Mavericks needed too many games to figure out themselves.

As Nick Nurse, now the coach of the Philadelphia 76ers, once said: “If it gets to 3-1, it’s not 3-0 anymore. And 3-1 has been done.” There are adjustments upon the adjustments to be made, ones Boston certainly will make from a Game 4 that was a lackluster performance from a team that could be spraying champagne as soon as Monday’s Game 5.

It does show something that the Mavericks won this game so decisively. It does stand out as Horford admitted his team’s opponent has finally forced them back to the film room. Even if that’s partially media speak — there have been countless small adjustments already made by both teams, ones that Boston has made quicker, even as Dallas’ defensive scheme finally aced its zone principles in Game 4 to keep its centers nearer the rim — it nevertheless stands out.

Dallas, for the first time this series, wasn’t the overmatched team that floundered due to its countless self-created transgressions. It was the team that earned this spot to compete for history, one that may have simply come too soon for its players and its coaching staff. This is a series Dallas should regret not making more competitive if it ends in the same way that every other one featuring a 3-0 lead has before.

“We waited until Game 4 to ultimately play our best game,” Irving said. “But we have another opportunity to extend the season. That’s all we can ask for. We handled our business tonight. But the job is still an uphill battle, and we understand that.”

(Photo: Stacy Revere / Getty Images)