When the NBA Finals tip off Thursday night, the Warriors will be slight favorites to claim their fourth championship in the past eight years.

The Celtics, however, have more than a puncher’s chance to earn their record 18th title.

What exactly will either side have to do to win? The Post’s Brian Lewis breaks down the matchups that will decide what kind of series this is going to be:

Warriors’ 3-point shooting vs. Celtics’ 3-point defense

The only defenses that slow Stephen Curry, Klay Thompson and company are ones with no weak spot to hunt. That describes the Celtics. Boston had the best 3-point defense this season (33.9 percent) and it has gotten even better in the playoffs (31.7).

Edge: Celtics

Celtics’ 3-point shooting vs. Warriors’ 3-point defense

Boston outscored its foes by 11.0 points per game from deep in the playoffs, second-best in the league.

Edge: Celtics

Rebounding

The Celtics might not be dominant enough on the glass to force the Warriors to go big, but they can win the offensive rebounding battle, especially when Kevon Looney is off the floor. With Al Horford, Robert Williams III, Grant Williams and Daniel Theis, they can punish Golden State the way Dallas couldn’t.

Edge: Celtics

Drawing fouls and shooting free throws

Curry can get to the line when he wants. And even though Boston will try to pick on him on the other end, that’ll be tough with Gary Payton II available. Boston drew 31.3 free-throw attempts per 100 shots against Golden State, its second-best rate against any foe. Jayson Tatum’s rate (18 free-throw attempts, 35 shots) was his second-best against any team. But Thompson missed the first meeting, while Andrew Wiggins missed the second. Tatum will have to deal with both now.

Edge: Warriors

Warriors’ ability to get paint points vs. Celtics’ interior defense

Golden State shot 72.5 percent in the restricted area so far in the playoffs, third-best in the league. But that’ll be tough to do against a Celtics team that has held foes to just 98.5 points per 100 possessions with Williams on the court.

Edge: Celtics

Celtics’ ability to get paint points vs. Warriors’ interior defense

Draymond Green has allowed just 0.48 points per possession on isolations, No. 1 among all players who have defended at least 20 isolations, per Synergy Sports tracking. While Boston will hunt for looks against Jordan Poole, foes have shot just 38.3 percent versus Green.

Edge: Warriors

In transition

Both teams can get sloppy with the ball. The Celtics can force turnovers, but had too many empty possessions themselves against the Heat in the conference finals. Tatum committed 33 turnovers and Jaylen Brown added 23; nobody in the series had more than 12.

Edge: Warriors

Depth/bench

Boston can go nine deep, and can run a lot of big bodies at Golden State. But if the Celtics can’t force the Warriors to go big against their will, Golden State has more wing depth if it can go to the bench for the likes of Jonathan Kuminga, Otto Porter Jr. and Payton.

Edge: Even

Coaching

Ime Udoka has been a first-year revelation, but Steve Kerr is coaching in his sixth NBA Finals, and in what could be fourth-quarter nail-biters, that experience counts.

Edge: Warriors

Intangibles

Speaking of experience, five Warriors have been to the Finals, as opposed to not a single Celtic. Boston might have had the No. 1 offense and defense from Feb. 1 to the end of the regular season, but the postseason is a different animal. Golden State, outscored by seven points through the first three quarters in the playoffs, has been plus-94 in the fourth. That’s winning muscle memory.

Edge: Warriors