Boston’s Defense Flexed Its Muscles In Its Game 1 Win Over Dallas

The Boston Celtics‘ offense came out of the gates in Game 1 of the 2024 NBA Finals on fire. The numbers were undeniable: They shot 13-for-23 (56.5 percent) from the field, a scorching hot 7-for-15 (46.7 percent) from three, and nine of their makes were assisted in the first quarter. Kristaps Porzingis came off the bench and looked as good as you can after missing a month-plus with a hamstring injury, and was gigantic as the Celtics went from trailing the Dallas Mavericks by one point to opening up the largest lead after one quarter (17 points) in NBA Finals history. Outside of Jayson Tatum turning the ball over three times, everything was clicking.

And then, over the final three quarters of the game, the Celtic offense came back to earth a bit. From the second quarter on, Boston’s three-point shooting fell off — they only went 9-for-27 (a 33.3 percent clip) for the remainder of the game — and by the time they wrapped up a 107-89 victory, they team only posted an offensive rating of 115.1. All the caveats about one game vs. an entire season go here, but an offensive rating of 115.1 would have been 16th in the league this regular season, nestled right in between the Los Angeles Lakers and the Cleveland Cavaliers.

To be clear, Boston’s historically good offense (which had an ORtg of 122.2 this regular season) did more than enough to win on Thursday night, and the game state the rest of the way was largely determined by how well it performed in the opening 12 minutes. But the reason they won Game 1 so convincingly revolved around their performance on the other end of the floor. The Celtics’ defense was nothing short of magnificent from start to finish, as they did a brilliant job dictating the terms of engagement against a good but flawed Dallas offense.

The Mavs could not get much of anything going — their 89 points were the fewest they’ve put up in a playoff game this year. Their seven made threes and 27 attempts from deep were their second-lowest marks in a single game during the postseason. While Luka Doncic put up 30 points, Thursday marked the first time in his playoff career in which he only had one assist — his previous low in a single playoff game during Dallas’ run to the Finals this year was five.

The thing that makes Doncic such a special basketball player is not his relentless ability to score, although that is certainly a part of the equation. It’s his ability to make his teammates better just by how he gives them the basketball. Guys like Doncic (or LeBron James, or Nikola Jokic, or any of the special playmakers that we’ve seen in the league over the years) are able to use their gravity and their ability as passers to get ball into the hands of their teammates in the exact spot — both on the floor and in the shooting pocket — that they want. Doncic’s passing opens things up for his teammates, who hit shots, who open things up for Doncic, which leads to a cycle that overwhelms opponents.

Boston’s solution to this: Take away the stuff that the Mavs want on the other end of Doncic’s passes. The point has been made, over and over again, that Joe Mazzulla wants the Celtics to win the math game, that he understands three points is worth more than two points, and as a result, they attempted more threes per game than anyone else in the NBA this season. Jason Kidd also understands this, as Dallas was second in attempts per game on the year. The Mavs especially place a premium on getting guys like P.J. Washington and Derrick Jones Jr. looks from the corner — Dallas led the league with 11.3 attempts per game from the corner. A remarkably high 65.5 percent of Jones’ three-point attempts this postseason come from the corner, while that number is 57.8 percent for Washington.

Again, when those guys hit those shots, the court becomes larger. There is more space for Doncic and Kyrie Irving, which opens up more space for themselves and for the lobs to Daniel Gafford and Dereck Lively Jr. that have become such a threat this postseason. Instead, Boston just cut their water off entirely — as a team, the Mavs went 1-for-3 on corner triples, and you can read a very good breakdown of how they did that via Joe Viray of SB Nation right here. Gafford and Lively combined for four total field goal attempts — they made all of them, but two were putbacks, one came off of a Doncic pass, and one came off of a pass by Washington. Beyond the fact that Doncic only had one assist, Tim MacMahon noted that Mavs players only shot 1-for-6 off of shots he got them — if Luka Doncic is only able to generate six shots for his teammates, Dallas has absolutely no chance to win this series.

Mixed with the fact that Boston’s defense smothered Irving — he went 6-for-19 from the field, missed all five of his attempts from three, and did not have an especially good time against the duo of Jrue Holiday and Derrick White — we witnessed a defensive masterclass from the Celtics, one in which they were happy to let Doncic get his as a scorer and nothing else really worked. It’s the unique problem Boston causes teams, and is why they were second in the league in defensive rating. When they are all locked in, the six guys they lean on the most (White, Holiday, Jaylen Brown, Tatum, Porzingis, Al Horford) all range from “very good” to “elite” on the defensive end of the floor. There just aren’t a ton of places to consistently attack, and even Sam Hauser was able to get the better of Doncic at one point in the game.

Trading for Holiday and Porzingis wasn’t viewed as an especially big risk because of how well they fit into the Celtics’ existing infrastructure, and while we saw that pay off all regular season, Porzingis’ injury in the first round meant that it had been a minute since we saw exactly how good the Boston defense is at its absolute best. Game 1 of the NBA Finals was not just a reminder, it was an emphatic statement that the Mavs have quite the uphill task ahead of them. Doncic and Irving are two of the league’s best problem solvers, and it’s certainly possible that they’re going to find something to exploit between now and the start of Game 2. But if they can’t — or, if they can but Boston has an answer for it — the Celtics defense is going to lead the way to a championship.