LeBron James chose the 76ers because he believes their new-look roster offers the best available opportunity to push for a final NBA championship.

And the window is small because James’ contract fits his age.

The 41-year-old signed a “one-plus-one” deal, also known as a two-year, $8 million contract with a player option for the second season. That forced the Sixers to do some roster tinkering for salary-cap purposes, waiving guard Dalen Terry before officially signing James on Sunday.

It is fitting that James is likely to be in Philadelphia for two seasons. At all three of his title-winning stops, he accomplished that feat in his second year.

For those eager to proclaim that the Sixers are immediately in championship-or-bust mode for the 2026-27 season, let history serve as a reminder that it can take time for even a star-studded roster to figure things out.

Here is how James reached the NBA mountaintop at each previous stop:

2010-12 Miami Heat

• 1st season

After “The Decision” teamed James with Dwyane Wade and Chris Bosh to create the “Big Three” in Miami, the Heat turned an infamously shaky 9-8 start into 58 victories and the Eastern Conference’s No. 2 seed. James, Wade and Bosh all made the All-Star team.

Miami advanced to the NBA Finals, beating the Sixers in the first round along the way. But the Heat lost to the Dirk Nowitzki-led Dallas Mavericks, falling short of a championship in the first season of the “Heatles.”

• 2nd season

Following the NBA lockout, the Heat finished 46-20 and second in the Eastern Conference standings at the end of the shortened regular season. James won his third NBA Most Valuable Player award, and his first with the Heat. James, Wade and Bosh were All-Stars once again.

In the playoffs, Miami beat the Boston Celtics in a thrilling seven-game Eastern Conference finals series. Then the Heat topped the upstart Oklahoma City Thunder – then led by a young Kevin Durant, Russell Westbrook and James Harden – to win James’ first NBA championship.

Though that Heat team did not accomplish the “not five … not six … not seven …” declaration from James’ flashy Miami introduction, it did win back-to-back titles and reached four consecutive NBA Finals before he returned home to the Cleveland Cavaliers.

2014-16 Cleveland Cavaliers

• 1st season

James’ new “Big Three” with Kyrie Irving and Kevin Love also got off to a slow start at 19-20. After trading for J.R. Smith, Iman Shumpert and Timofey Mozgov during the season, the Cavaliers finished second in the Eastern Conference standings with a 53-29 record. James and Irving both made All-NBA teams.

Cleveland advanced to the NBA Finals but lost to the Golden State Warriors to begin that team’s dynasty.

• 2nd season

The Cavaliers underwent a critical midseason shakeup when, despite holding the Eastern Conference’s best record at the time (30-11), they fired coach David Blatt in January. They promoted then-assistant Ty Lue, who has since become one of the NBA’s most respected coaches. Cleveland went on to finish the regular season 57-25 and atop the Eastern Conference.

That playoff run culminated in an unbelievable, storybook NBA Finals against the Warriors. The Cavaliers became the first team to overcome a 3-1 Finals deficit and won a dramatic Game 7 to deliver the franchise’s first NBA championship. James’ crunch-time block on Andre Iguodala, which preserved a tie before Irving’s go-ahead 3-pointer, is considered one of the greatest defensive plays in NBA playoff history.

James stayed with Cleveland for two more seasons – reaching the Finals each time to extend his personal streak to eight consecutive appearances – but the Cavaliers lost to Golden State both times.

2018-20 Los Angeles Lakers

• 1st season

James joined the Lakers in free agency, signing with a team built primarily around young players, including Brandon Ingram, Lonzo Ball and Josh Hart. They slogged through an injury-riddled 2018-19 season – James played only 55 games – and missed the playoffs. It was the first time since 2006 that a James-led team failed to reach the postseason.

Team president Magic Johnson stepped down at the end of the season during an abrupt and now-famous “I’m not gonna be here” news conference, and coach Luke Walton and the team also parted ways.

• 2nd season

Under promoted executive Rob Pelinka, the Lakers acquired star big man Anthony Davis in a blockbuster trade and added former Sixers Danny Green and Dwight Howard as veteran complements.

The Lakers recorded the Western Conference’s best record (52-19) during a regular season interrupted for more than four months and later shortened because of the onset of the COVID-19 pandemic. James and Davis were both named first-team All-NBA.

The Lakers’ “bubble” playoff run at Disney World ended with them defeating the Heat to clinch the storied franchise’s first NBA title since 2010. Some critics will put an imaginary asterisk next to it. But it will likely go down as the most unusual circumstances under which any NBA team has won a championship.