Here lie the N.B.A.’s most compelling story lines.

Potential contenders in the Eastern Conference scrambled during the off-season to assemble teams fit to knock off Giannis Antetokounmpo — now with a new, improved jump shot? — and the reigning N.B.A. champion Milwaukee Bucks. Even the conference’s perennial bottom feeders built rosters that will demand attention from basketball devotees. Some teams are just hoping that distractions don’t derail their seasons before they start.

Many wonder how the Ben Simmons situation in Philadelphia will end. The 76ers seemed locked in a stalemate with Simmons, a three-time All-Star, who has wanted to be traded for months. Simmons ended his holdout midway through the preseason and reported to the team but has not played. The 76ers have said they want him on their roster, but if they persuade him to stay, can they really go forward with business as usual?

Meanwhile, the Nets have a bona fide championship roster. They know this, and even with the distraction of Kyrie Irving’s murky status because he’s not vaccinated, they expect to hoist the Larry O’Brien championship trophy at season’s end.

Could the N.B.A.’s balance of power, which has long rested in the West, be shifting to the East? Here’s a look at how the Eastern Conference shapes up this season.

Miami Heat

By Scott Cacciola

In some ways, it seems so long ago. But little more than a year has passed since the Heat plowed their way to the 2020 finals before losing to the Los Angeles Lakers. Was it a fluke, aided by playing under the unusual conditions of a bubble environment, with no fans? The Heat were up and down last season before the Milwaukee Bucks ejected them from the 2021 playoffs in a lopsided first-round series.

Jimmy Butler needs to be efficient. Duncan Robinson needs to be consistent. Tyler Herro needs to recapture his assertiveness. And Bam Adebayo needs to keep making the sort of strides that have pushed him toward becoming a perennial All-Star.

The team should benefit from two additions: Kyle Lowry, who at 35 left the Raptors after nine seasons, and P.J. Tucker, who helped the Bucks win the championship last season.

Philadelphia 76ers

By Alanis Thames

Ben Simmons is, for now, back in the City of Brotherly Love.

Simmons, who reportedly demanded a trade in late August and missed training camp, reported to the 76ers ahead of their third preseason game but did not play. Simmons’s future in Philadelphia remains unclear, though. He still has four years left on his maximum contract.

With or without him, Philadelphia is antsy to win now. Joel Embiid is coming off the best season of his career, when he finished second in the voting for the Most Valuable Player Award. The 76ers were the No. 1 seed in last season’s Eastern Conference playoffs but collapsed in the semifinals, continuing their inability to turn regular-season wins into deep postseason success.

Philadelphia is a better team with Simmons, 25, despite his offensive shortcomings. But even if he doesn’t play anytime soon, Embiid, Seth Curry, Danny Green and Tobias Harris should be experienced enough to keep the Sixers in contention.

New York Knicks

The Knicks doubled down on last season’s roster, which unexpectedly made the playoffs then flamed out — albeit after a brilliant flare — in the first round. The veterans Derrick Rose and Taj Gibson are back, but Elfrid Payton, who triggered an influx of gray hairs for fans, is not. The additions of Evan Fournier and Kemba Walker are significant, and should help take the offensive load off RJ Barrett and Julius Randle, who signed a four-year contract extension in the off-season.

This feels like a make-or-break year for the 23-year-old Mitchell Robinson, the center who is up for an extension and can jump through the roof. At his best, he protects the rim and is an excellent roll man. But he has had difficulty staying healthy. Look for bigger roles for Immanuel Quickley and Obi Toppin, who each showed promise off the bench as rookies last season.

The Knicks should easily make the playoffs, but their bench depth is a question mark.

Milwaukee Bucks

By Scott Cacciola

The Bucks kept the band together. Same coach. Same star. Same core — mostly. And why not? Fresh off their first championship since 1971, the Bucks seem poised for a title defense.

The challenge could be fatigue. Because of the pandemic, their postseason run stretched into July, and two starters — Khris Middleton and Jrue Holiday — helped the U.S. Olympic team win gold in August. The Bucks also lost P.J. Tucker, invaluable in the late stages of last season, to the Heat in free agency.

But Giannis Antetokounmpo, the two-time M.V.P., is still the face of the franchise and the proud owner of a newly minted championship ring. And he may be better than ever, showing off an improved jump shot in the preseason. With a contract that runs through the 2025-26 season, he is not going anywhere anytime soon.

Atlanta Hawks

After a surprising run to the Eastern Conference finals last year, the Hawks enter the season with the burden of expectations and the benefit of continuity. This team is deep and should compete to be one of the best in the East.

Most of the key players are back. The Hawks locked in their two best players, Trae Young and John Collins, with long-term extensions. Coach Nate McMillan will be running the team from opening night, as opposed to being thrust into the job midseason as he was during the last campaign after Lloyd Pierce was fired.

Atlanta almost pulled off a miracle run to the N.B.A. finals last season, after taking down the Knicks and the Philadelphia 76ers, but were bedeviled by injuries against the eventual champions, the Milwaukee Bucks. Players who were unavailable or not 100 percent, like De’Andre Hunter, Cam Reddish and Bogdan Bogdanovic, are expected to start the season with clean bills of health. The Hawks also added some quality veteran bench pieces in Gorgui Dieng and Delon Wright, and an intriguing rookie they drafted late in this year’s first round, Jalen Johnson.

Charlotte Hornets

By Alanis Thames

LaMelo Ball, last season’s rookie of the year, highlights Charlotte’s promising young core. He’ll likely be the Hornets’ primary facilitator and already has great court vision and playmaking ability, and he is continuing to improve his jump shot.

Ball and forward Miles Bridges in the pick-and-roll were elite last season, with Bridges’s power at the basket and Ball’s precise lob placement on display. That pairing should only be better this season.

The Hornets already had solid veterans in Terry Rozier and Gordon Hayward, and they added Kelly Oubre Jr. and Mason Plumlee. Oubre is an inconsistent shooter, but could be impactful in transition. Plumlee is a versatile big man.

This group won’t be knocking at the door of the N.B.A. finals this season, but the Hornets will be a fun team to watch, and have a real chance at a playoff berth.

Brooklyn Nets

With the addition of Patty Mills and Paul Millsap, as well as the return of Blake Griffin and LaMarcus Aldridge, the Nets, on paper, are one of the best teams in N.B.A. history. In normal circumstances, they would be title favorites, given their Big Three of Kyrie Irving, James Harden and Kevin Durant. But that was the case last year too, and the Nets bowed out in the second round of the playoffs.

Health will be the principle factor for determining how far the Nets go. All of the Nets’ top players have significant miles on their legs and have missed substantial time in recent years.

If there is a potentially weak point for other teams to exploit, it is defensively, where the Nets struggled last season, and their off-season additions didn’t seriously address that. This could come back to bite them in the postseason, particularly in the frontcourt against players like Milwaukee’s Giannis Antetokounmpo, who scored at will during last year’s playoffs, or Philadelphia’s Joel Embiid.

But the offensive firepower is top notch. It’s hard to see the Nets being beaten in a seven-game series if they’re healthy.

Chicago Bulls

By Alanis Thames

Chicago could be a sneaky-good team this season.

Arturas Karnisovas, the Bulls’ executive vice president of basketball operations, voiced displeasure with the team’s 31-41 record shortly after last season. Since then, he’s added DeMar DeRozan, Lonzo Ball, Alex Caruso and Tony Bradley to a roster with Zach LaVine and Nikola Vucevic, whom Chicago acquired from Orlando at the March trade deadline.

DeRozan is lethal in the midrange, but some have questioned how he’ll fit with LaVine, as both players are most effective with the ball in their hands. Chicago will have an upgrade at point guard with Ball, who is a deft passer. And Caruso will add a rugged spark off the bench. Coach Billy Donovan will have to figure out how they all fit on the court.

In any event, Michael Jordan said that with the changes the Bulls made, they could compete in the East. How long has it been since those words were last spoken?

Toronto Raptors

It’s a new era in Toronto basketball. Kyle Lowry, perhaps the most lauded Raptor in franchise history, has gone to Miami. Without him, the Raptors are likely stuck between being too talented to get a top draft pick and not being so good that they’ll contend for a top seed in the conference.

But there may be an opening for Toronto in the turbulent East: Scottie Barnes, whom the team surprisingly drafted at No. 4 this year, showed potential in the preseason. And the Raptors’ frontcourt, helmed by Chris Boucher and the newly acquired Precious Achiuwa, will be a force.

There are lots of questions for the Raptors entering the season: Is Pascal Siakam, who is expected to miss the start of the season as he recovers from shoulder surgery, a true franchise cornerstone? Will Lowry’s replacement at guard, the 35-year-old Goran Dragic, last the season in Toronto? Or will Masai Ujiri, the Raptors head of basketball operations, flip Dragic’s expiring contract?

Detroit Pistons

By Alanis Thames

You’d be hard pressed to find any Pistons fans who haven’t already crowned the rookie guard Cade Cunningham as their Magic Johnson. Johnson, of course, won an N.B.A. title as a rookie after the Lakers drafted him No. 1 overall in 1979.

Detroit drafted Cunningham, a savvy scorer and shot creator, No. 1 overall earlier this year to hopefully lift itself out of years of irrelevancy. An ankle injury sidelined him in the preseason, and the team is being cautious.

Detroit’s young group showed promise last season, despite finishing with the worst record in the East, but the Pistons are another team in rebuilding mode. Coach Dwane Casey has said that this season’s goal is to earn a spot in the postseason play-in tournament.

Cleveland Cavaliers

By Scott Cacciola

Only someone like LeBron James could render an entire franchise into an afterthought. But that was what he effectively did when he departed the Cavaliers for the glamour of Hollywood in 2018, leaving them to rummage through the wilderness without him. The Cavaliers instantly went from title contender to lightweight, though the team has some up-and-comers — highlighted by Collin Sexton and Darius Garland in the backcourt — who are cause for cautious optimism.

None of this is to suggest that the Cavaliers will come anywhere close to sniffing the playoffs. But a slow, steady rebuild — augmented by smart draft picks — is the way back to respectability. And there is more good news: Kevin Love (remember him?) has just two seasons remaining on his gargantuan deal, which could make him a more appealing target on the trade market.

Boston Celtics

By Scott Cacciola

From the start of training camp, Ime Udoka, the Celtics’ first-year coach, has had a particular emphasis: ball movement. He does not want the ball to stick. He wants his players to work together to generate the best shots.

This must have been welcome news to fans who got tired of watching the Celtics’ offense devolve into isolation sets last season. Jayson Tatum, 23, and Jaylen Brown, who will turn 25 this month, form one of the most talented young tandems in the league, but fulfilling their promise in the postseason has so far eluded them.

Perhaps Udoka can help them deliver. He replaced Brad Stevens, who moved to the front office after a posting .500 record and losing in the first round of the playoffs in his eighth season as the team’s coach.

Washington Wizards

Wes Unseld Jr., Washington’s new head coach, has a tall task ahead of him.

The Wizards are not a championship-caliber team, even after adding solid veterans like Spencer Dinwiddie, Kentavious Caldwell-Pope, Kyle Kuzma and Montrezl Harrell. So this season will be mostly about persuading Bradley Beal, who can become a free agent next summer, to make a long-term commitment to the franchise.

It’s hard to win without multiple elite playmakers, and the Wizards have just one in Beal after trading Russell Westbrook to the Los Angeles Lakers. But even in a yet another bridge year, the Wizards should, at the very least, have a playoff team. They’ll have the promising center Thomas Bryant back from injury, and the team can hope for some growth from its last two lottery picks, Deni Avdija (2020) and Rui Hachimura (2019).

Orlando Magic

By Alanis Thames

The Magic have a young team with a first-year head coach in Jamahl Mosley. They’ve made just two playoff appearances in the past nine seasons, and traded away their best players, Aaron Gordon and Nikola Vucevic, in the middle of last season. Then they landed Gonzaga’s Jalen Suggs at No. 5 in this year’s draft.

Suggs joined a roster that is crowded at guard, with Markelle Fultz, who will return from a knee injury, RJ Hampton, Terrence Ross, Cole Anthony and Gary Harris. Suggs probably has the highest ceiling of those players, though, and he was solid in the summer league before injuring his thumb.

The Magic will not be legitimate contenders for a while, so they have plenty of time to sort out their roster.

Indiana Pacers

By Scott Cacciola

Rick Carlisle, back for his second stint with the Pacers, is the team’s third coach in three seasons. Indiana could use some stability to help develop a young core that includes Malcolm Brogdon, Myles Turner and Domantas Sabonis, already a two-time All-Star at 25.

But the Pacers, who have not advanced past the first round of the playoffs since 2014, are coming off a 34-38 season, and Caris LeVert is out indefinitely with a stress fracture in his back.

Carlisle coached the Pacers for four seasons, from 2003 to 2007, while guiding them to three postseason appearances. It will take some hard work to get them there again.