NBA Finals betting preview: Are Celtics rightfully big favorites?

The Celtics' statistical dominance has led them to open the NBA Finals as massive -225 favorites (69% implied probability) and the Mavericks as +180 underdogs (36% implied probability).

Boston is 76-20 overall, 12-2 in the postseason, and has a net rating on par with the 2017 Warriors and 1996 Bulls, two of the greatest basketball teams ever assembled. Should the Celtics be in that category? Probably not, but their historically dominant starting lineup, switchable and swarming defense, and an unusually weak and depleted Eastern Conference put them in the statistical conversation.

NBA Finals favorites won seven of the last 10 championships. Recent winning underdogs include the 2019 Raptors, who played a Warriors team missing Kevin Durant for most of the series and Klay Thompson for significant stretches, and the 2016 Cavs, who pulled off a miraculous comeback after going down 3-1. In other words, oddsmakers have been pretty darn accurate.

For Game 1, the Celtics are 6.5-point home favorites and the over/under is 214.5. The series spread is Celtics -1.5 (+100) and Mavs +1.5 (-120), while the over/under is set at 5.5 games (-150). The exact game odds are as follows:

NBA Finals pick

There's understandable skepticism about the Celtics: They've previously failed to live up to expectations, they've enjoyed an easy path to the Finals, and you could write a book about their two superstars' playoff shortcomings. Thus, over 80% of bets are on the Mavs to win.

However, this isn't the Celtics team of years past. While Jayson Tatum and Jaylen Brown remain the cornerstones, now they're surrounded by players who elevate the duo's strengths.

Celtics fans can't forget the image of Tatum settling for step-back threes late in games, and there's a popular myth that this iteration of Boston struggles in crunch time. But they were actually the NBA's fourth-best clutch team this season, outscoring opponents by 15.4 points in the clutch (the Mavs were third-best). This postseason, Boston is the best clutch team with a 43.9 net rating (though it's only been in clutch situations four times in 14 games).

The Celtics' overreliance on threes could present a problem; almost half of their field-goal attempts are threes. Boston could exemplify "live by the three, die by the three." Except the Celtics haven't just lived by the three - they've prospered from it, owning the second-best percentage from beyond the arc during the regular season.

Boston's shooting 37% from three in the playoffs and almost always plays lineups with five guys willing and able to drain triples. Dallas flourishes at protecting the rim but struggles to defend threes; the Mavs rank in the bottom half of playoff teams in opponent 3-point percentage.

Dallas does clearly have the best player in the series: an unstoppable, deliberate force that can will the Mavs to a ring. Luka Doncic's propensity to tear apart defenses in the closing minutes has carried the Mavericks this far.

Tatum and Brown will initially guard Doncic. They have the length and strength to potentially slow down the Slovenian, although no one can stop him. Derrick White and Jrue Holiday - All-Defensive team selections - will be tasked with shutting down Kyrie Irving.

Kristaps Porzingis will determine the outcome of this series. He hasn't played since April 29 but is expected to be ready for Game 1. It's unclear if he'll be on a minutes restriction. The Celtics' dynamic completely changes if he's healthy. His stretching ability as a pick-and-pop threat and reliable post presence adds a new offensive layer (more on that in our player prop breakdown) and his defensive presence as a rim-protector who's also capable of guarding on the perimeter is crucial.

Derrick Jones Jr. and Daniel Gafford - who both start for the Mavericks now - played seven and six minutes, respectively, in these teams' last regular-season matchup March 1. There's not much to take away from the Celtics' blowout win besides noting how Boston guarded Doncic's pick-and-rolls: Porzingis played drop coverage and rarely blitzed. The Wolves' defense was most effective against the Mavs with Rudy Gobert in drop as well.

Al Horford doesn't provide the same defensive versatility and mobility as Porzingis, and teams have targeted the veteran's slow feet in ball screens the entire postseason. The Mavs, whose offense relies heavily on pick-and-roll actions, will try to torch Horford, making Porzingis' presence essential for Boston.

Home court is mostly irrelevant in this series. While the boos will be louder for Irving than any other player in TD Garden, the Celtics have been better on the road in the last three playoffs. The Mavs are 7-2 away from home and 5-3 at home this postseason.

A Mavericks win wouldn't be the first time individual talent plus the perfect sidekick and a supporting cast on a hot streak propelled a team to the championship. Doncic will be the best player on the floor in every game, and that's often hard to overcome at this stage. But the Celtics are the better team and have a deeper arsenal of reliable weapons. Boston has no tangible flaws other than questions about a closer (which the team may have answered already) and shot selection in the waning seconds of tight games.

Tatum, Brown, and the Celtics' crew have earned enough playoff scars. This is the year they finally exorcise their demons and lift the Larry O'Brien Trophy.

Pick: Celtics -1.5, Celtics in 6

Sam Oshtry is a sports betting writer at theScore. You can follow him on X @soshtry for more betting coverage.