The Boston Celtics sit on the verge of a record 18th NBA championship, but the Dallas Mavericks gave pause Friday night by posting the third-largest blowout in Finals history. We look ahead to Game 5 with our Mavericks vs. Celtics prediction analysis.

The Boston Celtics had an NBA Finals sweep within their sights, but that never seemed like the natural end to their team’s story.

Even though Boston dominated the regular season and the Eastern Conference playoffs, it has never been given the respect of a team with its resume, for circumstances both in the team’s control (the lack of elite clutch play) and out of it (their relatively easy path in the postseason). There also are the memories of falling short with this core in recent postseasons that still linger in everybody’s mind.

But this Celtics team has three more shots to prove it is different.

The Dallas Mavericks have pumped a little life into the series by doing the opposite of rolling over and running the Celtics out of American Airlines Center Friday night, winning a 122-84 laugher in Game 4 – the third-largest margin in Finals history. And the Celtics – the best problem-solving team in the league all season due to its versatility and depth – has one more problem to solve before being crowned champions for what would be a record 18th time (they’re currently tied with Lakers at 17 titles apiece).

A Game 5 when the home team is up 3-1 is always interesting. The visitors are still the more desperate team, but the sense of urgency increases for the home team. In this case, the Celtics don’t want to face the prospect of a Game 6 in Dallas that could even the series.

The Mavericks’ margin of error is still slimmer, of course, but with Celtics standout Kristaps Porzingis’ health still hanging in the balance, there are a lot of intriguing questions heading into Monday night’s Game 5 tipoff at TD Garden (8:30 ET, ABC).

Our win probability model still rightfully gives the Celtics a 97.6% chance to win the Finals because, well, no team has ever come back all the way after dropping the first three games of an NBA playoff series.  

The Boston Celtics are seeking a record 18th NBA championship under second-year coach Joe Mazzulla.

Looking Lively

It was understandable for a rookie, but Mavericks big man Dereck Lively II looked lost in the first couple games of the NBA Finals – especially defensively.

Lively was too aggressive both in helping in rotation and on pick-and-rolls, and it allowed Boston to leverage him being out of position into easy baskets. The Celtics already pose such a challenge with how often they play 5-out offense and get shot blockers away from the rim. If a big man defending them isn’t disciplined, he’s not going to impact plays – and Lively didn’t impact much at all in the first two games.

When the Finals shifted to Dallas, Lively found his footing. He still doesn’t have a block in the series, but he’s impacting the game again on defense:

This Mavs rotation above works because Lively doesn’t move too soon. Had he come as soon as Boston’s Jaylen Brown begins his drive, there would be an easy pass to Derrick White in the corner for either a 3-pointer or the start of a mad scramble of a defensive rotation. Lively instead waits until Brown is in the paint and close to releasing a shot, and that makes the timing and angle of the pass much harder.

Brown’s pass is offline, making White’s subsequent pass to Jayson Tatum a fraction of a second later. Even though the Mavericks send two help defenders to Tatum, it’s late enough in the shot clock that he can’t get the passing angle he wants in time to prevent the clock violation.

This postseason, the Mavericks have been better with Lively on the floor versus any lineup with Daniel Gafford at center or Maxi Kleber as the lone big. He entered the Finals with one of the best plus/minus ratings in NBA playoff history.

Lively returning to defense closer to most of his postseason has allowed him to stay on the floor, and his passing out of the short role and activity have helped breathe some life into the Mavericks offense, which has been stagnant too often in the Finals.

The big question for Lively is whether he can keep playing as effectively as action shifts back to Boston. This also goes for Dante Exum, who hit a couple of shots in the second quarter of Game 4 and looked to provide at least something off the Mavericks bench. Additionally, Tim Hardaway Jr. finally hit some shots when the game was well in hand in the fourth quarter.

Will Mavs coach Jason Kidd give a bench player another shot if their offense needs a jolt in Game 5? Getting solid contributions from anyone on the road not named Kyrie Irving or Luka Doncic would be massive.

And it starts with Derrick Lively.

Two-Way Turnaround

Lively’s bounce back is really important for Dallas, but the team isn’t built like the Celtics. The Mavericks have a top-heavy roster, and the most important part of their success lies with the two stars.

Doncic’s Game 4 was reminiscent of Boston’s star’s performance through the first three games. Tatum didn’t have the best surface-level stats to start the series, but that was due in large part to a jump shot that hasn’t been falling consistently. The most important part of his productivity has been an ability to get into the Dallas defense and force rotation.

Doncic’s tape told a similar story in Game 4. Without Porzingis’ shot blocking presence, the Celtics have been a little itchier to help on drives to the basket, and that finally started to show some cracks in the defense. He may have scored only 29 points due to subpar 3-point shooting, but Doncic put the Celtics in rotation enough to generate better looks than the Mavericks have gotten all series.

Doncic also turned the ball over just once, matching his low in the playoffs after he had averaged five per game in the first three games of the Finals. Not allowing the Celtics to get running after live ball turnovers contributed to their offensive woes.

Defensively, Doncic put up more of a fight and did so without the glaring foul issues that probably cost Dallas a Game 3 win. Obviously, he was less likely to pick up a frustration foul when his team was up comfortably most of the game, but he’ll have to carry that composure and effort into the rest of the series.

Irving was quiet compared to his explosion in Game 3, but he also committed just one turnover and played mostly mistake-free. He has ramped up his defensive effort as well – he still gets bodied occasionally by the bigger players on switches, but his effort to contain penetration has been needed.

The concerning issue about the Mavericks stars’ play has been shooting. After Doncic went 8 for 21 on 3-pointers in the first two games in Boston, he was 1 for 15 behind the arc in the past two games. Irving was 4 of 6 on 3s in Game 3, but also a combined 1 of 14 in the other three games.

Is this an aberration or is the increased defensive effort combining with the duo’s massive offensive responsibility causing fatigue to the point their jump shots aren’t going to be reliable the rest of the series?

The Game 4 blowout provided some much-needed rest for Doncic and Irving, who both played under 33 minutes. It’s unlikely either will get much rest the remainder of the series.

It’s hard to see the scenario coming as easily for the Mavericks offense in Game 5 as it did Friday night They’ll likely need better jump shooting from Doncic and Irving to stay alive.

The Dallas Mavericks led by as many as 48 points in their 122-84 blowout of the Boston Celtics in NBA Finals Game 4.

Boston’s Process

Of course, Dallas might be able to afford an offensive downturn in Game 5 if the Celtics score only 35 points in the first half, like in Game 4.

While their offense has struggled at times in the Finals, it’s not necessarily due to the process, as the Celtic generated good shots, but just missed a lot of 3-pointers.

You’d assume they’ll be able to hit enough 3s in one more game to seal the title, but Game 4 was different as Dallas truly stifled the Boston offense for the first time:

  • Boston’s starters had 12 assists and 11 turnovers, while as a team, the Celtics had their fewest assists (18) and matched their turnover high (14) in the Finals;
  • Brown, the Finals MVP favorite, shot just 3 of 12;
  • Point guard Jrue Holiday, whose play against mismatches has been integral in Boston’s success in the Finals, had an awful offensive game with five turnovers (and a few of the head-scratching variety);
  • The 84 total points matched the Celtics’ low in their last 93 postseason games since 2018;

Some of the Celtics’ struggles was due to poor play, some to Dallas’ better defense and some to not having Porzingis around to help ignite the offense. All three were evident on this one play:

Dallas did a better job of containing penetration most of the game, but that wasn’t the case above. On this play, Tatum blows by Lively, but Josh Green does a good job of recognizing early to help out, and Tatum’s decision to drive right into him isn’t a great one. But Tatum’s options are limited in part because P.J. Washington is in the right spot to help in the corner on Green’s man, and Doncic is in the right spot to help in between his man and Washington’s man.

This is a good rotation by Dallas, but it’s made easier by the fact Xavier Tillman, not Porzingis, is on the floor for the Celtics. Porzingis has hurt opponents all season with trail 3-pointers, and leaving him wide open is a five-alarm fire.

If the Celtics’ 7-foot-3 forward was available, Washington would likely be two steps closer to him, making his job as the initial helper much tougher. And Doncic might over-rotate once Washington leaves Porzingis open one pass away, which would create a pass to Brown.

Everything becomes more difficult without the floor spacing provided by Porzingis, but Boston still has enough offensive talent to overcome it if Porzingis misses another game due to injury. As mentioned before, Boston is too big, too skilled and too smart not to make strong adjustments, and it has two-way stars in Tatum, Brown, White and Holiday. While Tillman isn’t Porzingis, he’s serviceable enough as a rotation piece and is now providing the insurance the Celtics anticipated in trading for him.

Mavericks vs. Celtics Prediction: Game 5 Edge

Interestingly, Monday night’s game comes on the 16-year anniversary of the Celtics clinching their most-recent NBA championship in 2008.

It will be difficult for Dallas to keep its defensive intensity up for another game, and Boston can put pressure on the Mavericks’ execution of plays by making better decisions. Still, Dallas didn’t simply lie down and hand Boston the title, with the underdog proving the Celtics have to make one more game’s worth of adjustments.

But the Celtics are armed with such capability, so if they can match Dallas’ desperation, Game 5 should be the most interesting of the series.

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