LeBron James and the Cleveland Cavaliers open their title defense against the Indiana Pacers. (Brett Davis/USA Today)

It’s been an eventful regular season in the NBA. A new collective bargaining agreement was ratified, leading to labor peace for the next several seasons. An offensive explosion led to numbers the league hasn’t seen in decades — most notably Russell Westbrook averaging a triple-double for an entire season — and one of the most competitive MVP races of all time.

All of that, however, is in the past. The NBA’s postseason has finally arrived, and Saturday will begin two months of the highest-level basketball in the world, all of which will culminate in the NBA Finals in June. Will the Warriors win a second title in three years? Will the Cavaliers repeat? Will some team in either conference manage to unseat one of them and make it to the championship round?

Here’s a breakdown of the eight first-round series, and a prediction for how each will play out.

Eastern Conference

1. Boston Celtics vs. 8. Chicago Bulls

Celtics: Boston claimed the top spot in the East for the first time in nine years behind a tremendous offensive season from Isaiah Thomas, which helped mask a substandard point differential (3.1 per 100 possessions) for a top-seeded team.

Bulls: It’s been a bizarre season in Chicago, full of several wins versus good teams, several losses to awful ones and plenty of infighting in between, but the Bulls still managed to land the East’s final spot.

X-factor: Chicago’s Jimmy Butler is the best player in this series (no offense to Thomas, who was a third-team All-NBA selection by The Post), which gives the Bulls a puncher’s chance. Last year’s Toronto-Indiana series, when Paul George nearly stole it for the Pacers, is an example of how Butler could tip the scales in Chicago’s favor.

Boston guard Isaiah Thomas carried the Celtics to the top seed. Will the Bulls be able to stop him? (Charles Krupa/AP)

Celtics win if: Thomas continues to produce as he did during the regular season, and their offense doesn’t completely fall apart when he’s on the bench.

Bulls win if: Butler is the best player in the series by a country mile, the Bulls can hit some perimeter shots and are able to slow Thomas to some extent.

Prediction: This series should be closer than a lot of people would expect because of the records and seeds involved. Boston hasn’t proven it can make a playoff run, and Butler is good enough to make this competitive. He will, but Boston should survive in the end. Celtics in 6.

2. Cleveland Cavaliers vs. 7. Indiana Pacers

Cavaliers: Cleveland stumbled and bumbled its way into the playoffs, but still has the world’s best player in LeBron James and the most talent of any team in the East.

Pacers: Once looking like a team that could challenge for home court advantage, the Pacers fell apart down the stretch and snuck into the postseason on the final day of the regular season.

X-Factor: Cleveland’s defense has been awful, which many have chalked up to a lack of motivation. Is it that simple, or are there bigger issues? It’s time to find out.

Cavaliers win if: They stay healthy and motivated.

Pacers win if: Paul George plays like an MVP and James and other players get hurt.

Prediction: LeBron James is 40-7 all-time in the first round of the playoffs. He’s going to add four more wins to that total with relative ease. Cavaliers in 5.

3. Toronto Raptors vs. 6. Milwaukee Bucks

Raptors: Toronto is 17-8 since the all-star break — and that was mostly done without star point guard Kyle Lowry, who missed most of that time due to wrist surgery.

Bucks: Milwaukee was expected to miss the playoffs after losing Khris Middleton for half the year and Jabari Parker for the other half, but made the postseason because in his fourth season, Giannis Antetokounmpo has arrived as an NBA superstar.

X-Factor: Toronto has struggled in the playoffs the past few seasons, and it’s mostly been because of up-and-down play from Lowry. If their talisman brings it on a nightly basis, this team has the goods to give everyone in the East — Cleveland included — a very difficult time.

Raptors win if: Lowry and DeMar DeRozan perform the way they are capable of, and the strong post-all-star break defense continues.

Bucks win if: Antetokounmpo takes yet another leap forward in the postseason, Middleton shuts down DeRozan and Lowry short-circuits.

Prediction: The Bucks are a scary first-round opponent because of Antetokounmpo, but it’s hard to see Toronto losing this one with home-court advantage and a healthy Lowry. Raptors in 6.

4. Washington Wizards at 5. Atlanta Hawks

Wizards: After a 2-8 start, it looked as though the Wizards were destined for a second straight disastrous season, but they completely turned things around, winning the franchise’s first division title since 1979.

Hawks: The Hawks are a confusing team, but they come into the playoffs hot after beating Boston and Cleveland (twice) within the past week.

X-Factor: Paul Millsap has missed most of the past month with knee issues. If he is healthy, Atlanta can make this series interesting. If he’s not, it should be a walkover for Washington.

Wizards win if: John Wall and Bradley Beal play like they have in prior playoff trips and the team’s defense goes back to where it was pre-all-star break (ninth) as opposed to post- (27th).

Hawks win if: Millsap is healthy and the best player in the series, Dwight Howard dominates Marcin Gortat inside and the Wizards remain unable to stop anyone.

Prediction: Washington would’ve won this matchup two years ago if John Wall hadn’t gotten hurt. This Wizards team is better than that one, and the Hawks are worse. Washington will win this time. Wizards in 5.

Western Conference

1. Golden State Warriors vs. 8. Portland Trail Blazers

Warriors: Working Kevin Durant into the mix didn’t slow the Warriors, who became the first team in NBA history to win at least 67 games in three straight seasons.

Trail Blazers: Portland was floundering midseason before acquiring center Jusuf Nurkic from Denver. From that point the Blazers were a different team, and, ironically, stormed past the Nuggets and into the eighth and final playoff spot.

X-Factor: Portland isn’t winning this series. But if Nurkic is healthy (he’s been out two weeks with a non-displaced right leg fibular fracture), the Trail Blazers have a chance to make this series at least somewhat competitive.

Warriors win if: They stay healthy and all of their players show up.

Trail Blazers win if: Damian Lillard and C.J. McCollum combine to average 80 points per game, Nurkic is healthy and plays out of his mind and the Warriors suffer several injuries.

Prediction: The Warriors aren’t losing. Warriors in 4.

2. San Antonio Spurs vs. 7. Memphis Grizzlies

Spurs: Another season, another 60 wins for San Antonio, which has made the playoffs in 20 straight seasons and won at least 50 games in 19. (The Spurs went 37-13 in the lockout-shorted 1999 season.)

Grizzlies: Without Chandler Parsons and dealing with myriad injuries, Memphis grinded its way to yet another playoff appearance.

X-Factor: Tony Allen was listed as out indefinitely with a calf injury Thursday. If Memphis has a chance, it will need the all-world defender healthy to try to slow down Kawhi Leonard.

Spurs win if: They stick to what they do, and Tony Parker and Pau Gasol aren’t taken advantage of defensively by the Grizzlies.

Grizzlies win if: Mike Conley and Marc Gasol are the two best players on the court, Leonard struggles to hit shots and Memphis gets scoring from unexpected places.

Prediction: With Allen at less than 100 percent — or perhaps not available — the Grizzlies’ slim chances drop to basically none. Spurs in 5.

3. Houston Rockets vs. 6 Oklahoma City Thunder

Rockets: Mike D’Antoni’s famed offensive attack has revolutionized the team and made James Harden an MVP candidate. Eric Gordon is up for Sixth Man of the Year, D’Antoni could be Coach of the Year and Daryl Morey Executive of the Year after bouncing back from last year’s disaster.

Thunder: Despite losing Durant in free agency, the Thunder soldiered on behind a remarkable season from Russell Westbrook, who dragged the Thunder to 47 victories by becoming the first person to average a triple-double for a season since Oscar Robertson 55 years ago.

X-Factor: Steven Adams had a coming-out party during last year’s playoffs, using and abusing the Spurs and Warriors and making many people think he could push for an all-star berth this season. After a somewhat disappointing regular season, can he have a similar impact in the playoffs?

Rockets win if: Harden keeps D’Antoni’s offense humming, his supporting cast buries threes and Houston frustrates Westbrook and makes his teammates beat them.

Thunder win if: Westbrook runs amok, Adams and Victor Oladipo are able to take advantage of openings Houston gives them and Oklahoma City is able to use its size to rough the Rockets up inside.

Prediction: The Harden-Westbrook battle will be the most fun of the first round. But it’s hard to see how Oklahoma City will have the firepower to keep up with Houston. Rockets in 6.

4. Los Angeles Clippers vs. 5 Utah Jazz

Clippers: They started 14-2 but never again reached that level, and the impending free agencies of Chris Paul, Blake Griffin and J.J. Redick hang over them.

Jazz: Utah is in the playoffs for the first time in five years despite dealing with a nonstop series of injuries.

X-Factor: When George Hill is healthy, the Jazz are excellent. When he isn’t, they are ordinary. Facing one of the league’s best floor generals in Paul, Utah needs Hill to be healthy and productive.

Clippers win if: Paul dominates his matchup, Griffin and DeAndre Jordan control the paint and ancillary pieces such as Redick, Jamal Crawford and Marresse Speights give the Clippers more scoring than Utah can handle.

Jazz win if: Hill is healthy, Gordon Hayward is able to consistently deliver 25-plus points, Rudy Gobert dominates his matchup with Jordan, Derrick Favors is healthy and can play Griffin to something close to a draw.

Prediction: This should be the most competitive series of the first round, with what should be a relatively even amount of talent. The fact that the Clippers have won 16 out of 18 against the Jazz, though, shows Utah — with a team lacking playoff experience to boot — should struggle in this one. Clippers in 6.