The Celtics have neutralized the Mavericks defense’s biggest strength in the NBA Finals

The Mavericks defensive turnaround since the All-Star break isn’t rocket science: Dallas got bigger, longer, more athletic at the trade deadline, and loaded up the paint to wall off the rim, daring teams to punish them with three point shooting.

It wasn’t a bad gamble, because even the best three point shooters are only making anywhere from 40-48 percent of their open threes for the most part, while a league average percentage at the rim is around 64 percent. There is variance in shooting a jumper compared to scoring on a layup or dunk, and Dallas smartly leveraged its size to cut off the water on the most sustainable shot in basketball, so a slightly less reliable one might not kill them. That’s before even factoring in where those threes are taken and who are taking them, which is something Dallas has figured out pretty well.

Dallas’ defense almost demands perfection from the opposing five players on the floor, because the Mavericks pounce when there’s even one subpar offensive player sharing the floor. So what happens when a team can play five above-average offensive players for a full-48 minutes? Well, you have the Celtics taking some of the bite out of the Mavericks defense and a big reason they’re up 2-0 in the NBA Finals after a 105-98 win in Game 2 Sunday night.

After going a perfect 15-of-15 in the restricted area in Game 1, the Celtics went 20-of-27 in Game 2. Dallas entered the Finals only allowing opponents to make 59.6 percent of their shots in the restricted area in the first three rounds of the playoffs. Now the Celtics are not only winning the battle at the three point line (26 made threes to the Mavericks 13 in the two games), but they’re scoring well at the rim. Dallas has survived the three point gap up until now because the rim was entirely shut off. Now the Mavericks are giving up both.

What makes it worse is that Boston isn’t doing anything overtly complicated or complex: the Celtics aren’t a heavy pick and roll team, and they don’t have a dominant playmaker that’s impossible to deal with. Instead they just throw constant, consistent pressure at you from all five players on the floor and Dallas’ drive containment has been absolutely compromised due to how unique the Celtics rotation is. Lots of teams talk about shooting, spacing, and five-out play, but there is nothing remotely similar to what the Celtics roll out with Al Horford and Kristaps Porzingis at the five, always surrounded by four more shooters and capable drivers.

Entering the Finals, Mavericks opponents were shooting 59.6 percent in the restricted area, a number well-below league average. In the Finals, Boston is shooting 72.3 percent. Also consider this: none of the Mavericks opponents shot 50 percent or better on drives against the Mavericks in the first three rounds. In the Finals through two games, the Celtics are shooting 55.9 percent on drives, and creating assists on 11 percent of those drives.

Dallas cannot contain the point of attack, because the Celtics roster bends and warps the floor balance in such a way that it limits what Dallas is good at. If the Mavericks have their centers, either Daniel Gafford or Dereck Lively, on the Celtics center, that creates pick-and-pop and closeout mismatches or keeps Gafford and Lively away from the paint to contest drives. Dallas has tried “hiding” their centers on Jrue Holiday, but the Celtics are wisely using Holiday as a release valve in the dunkers spot and Holiday is attacking the big aggressively when the ball is swung to him. Holiday scored 26 points in Game 2, and only needed two made threes to get there — he shot 9-of-10 on twos.

Even when the Mavericks smartly switched in this scenario to keep Gafford near the rim, Jones has a reckless closeout that gets Holiday an easy two.

It wasn’t just Holiday that cooked, but seemingly every Celtics player was blowing by the Mavericks perimeter defenders. And then with the ridiculous spacing, the Mavericks basically asked their centers to be superhuman and cover more ground than they could. Dallas has tried switching its centers to guard those drives outright, but neither big has held up that end too well, and when a big gets beat on the perimeter, that means the backline help defense is small. Boston took advantage of that continually in Game 2.

On this play you can see what happens when the Mavericks big guards the Celtics center, in this case Lively on Porzingis. Lively doesn’t even factor into score at the rim for Boston because of the respect Porzingis demands behind the three point line.

The inability to contain drives doesn’t just lead to the points at the rim, but of course fuels the Celtics drive and kick game with all their elite shooters. Basketball writer Jared Dubin noted after Game 2 that the Dallas defense has delivered the three worst blow-by rates in the playoffs according to Second Spectrum data, with two of them being the two games played so far in the NBA Finals.

This Holiday three is a prime example of everything going wrong for Dallas — Luka Doncic is beat off the dribble by Jaylen Brown, who meets Gafford at the rim. That part is OK, the Mavericks have taken away the paint! Then the kickout happens, Josh Green and PJ Washington both closeout to one player (Derrick White), which then gives Jayson Tatum a clear angle to drive. Dallas surrenders two decent drives, forcing poor rotations that end in a Holiday corner three.

The Mavericks cannot cut off the head of the snake on these possessions, and the snowball effect is too great to overcome, because Boston’s elite spacing means the Mavericks bigs aren’t as readily available near the rim. Gafford and Lively are averaging 2.8 blocks per game combined in the playoffs, the duo only has one total in the NBA Finals.

As for adjustments, this part is difficult. Just…don’t get blown by? Easier said than done, of course, and part of Dallas’ defensive dominance since March has been the ability to compensate for the blow-bys with rim-protecting centers there to back up the perimeter players, and solid rotations from there. Most teams can give you an out, a player to cheat off of so those centers can roam. The Clippers had Terance Mann, Russell Westbrook, Miles Plumlee, and Amir Coffey. The Thunder had Josh Giddey and Lou Dort. The Wolves had Jaden McDaniels. Boston just doesn’t present that opportunity as easily, and the one player the Mavericks dared to score in Game 2, Holiday, scored a game-high 26 points. That’s why Boston is so tough. It’s not just the floor-spacing bigs, but every other starter is a quality driver against closeouts. Not only is there nowhere for the centers to hide to muck up the paint, there’s no where for Luka Doncic and Kyrie Irving to hide as well. Doncic has a 35.8 usage rate in the Finals, up from 31.3 in the first three rounds. He’s also getting progressively more injured and banged up — how much defense can you reasonably expect him to play when Boston’s defensive strategy is demanding him to soak up nearly every possession? Then you add in the person he’s guarding is one of White, Holiday, Tatum or Brown? That’s a buzzsaw scenario. That’s why Irving’s disappearing act in the Finals so far is so killer, Dallas needs Irving to be efficient so Doncic can save some energy for the defensive end of the floor.

Perhaps the Mavericks can actually dare the Celtics bigs to shoot them into a win — Porzingis and Horford are a combined 5-of-15 from three in the series. The Mavericks could keep their bigs in the paint, and see if those two make enough shots to make things uncomfortable. No option sounds great, and that’s why Boston won a league-best 64 games this season, that’s why they’ve only lost two games in the entire playoffs so far, and that’s why they posted one of the best net-rating seasons in NBA history. Dallas has its work cut out for them, but they should try to get back on track by finding the strength around the rim that got them to the Finals.