The Philadelphia 76ers and the Boston Celtics are slated to go toe-to-toe in the upcoming Eastern Conference semifinals, and their battle just might reignite an old rivalry that began more than five decades ago.

This all began when Wilt Chamberlain led the Philadelphia Warriors and later the 76ers — against Bill Russell’s Celtics throughout the 1960s. Their on-court combat went on for 10 seasons, which eventually put the rivalry to rest. But when Larry Bird and Julius Erving came along, it all picked up in 1980s like it never left.

Now, fast forward nearly four decades to 2018, and the upcoming series seems like it’s the first step towards another reincarnated rivalry between the two Eastern teams.  If you don’t follow the teams, or haven’t trailed their history, here are three reasons why fans should get ready for some Eastern Conference supremacy and the beginning of another revolutionary basketball war.

1. Youth Movement On Both Teams

The 76ers have been living off their trust-the-process mantra ever since diving into the tank for high draft picks, and while said process certainly is not complete, an improvement of 24 wins over last year to the third seed in the Eastern Conference is, indeed, a very impressive step. Ben Simmons and Joel Embiid are two of the best 15 players in the league. Both young and nowhere near their prime.

With the Celtics also on the rise, albeit now without perhaps their two best players in Kyrie Irving and Gordon Hayward, their future seems relatively bright. Jalen Brown and Jayson Tatum have grown up in front of our eyes from young rookies to extremely important role players for a championship level team.

2. Eventual Roster Upgrades

Slowly but surely, the balance of NBA power is shifting to the Eastern Conference. Both the 76ers and the Celtics have great front office personnel and can adapt on the fly. Boston still has a ton of draft picks and other assets, that they can package to a San Antiono for a Kawhi Leonard.

Philly has a ton of salary cap space at their disposal. Now that the 76ers look like an upside team, many free agents might consider Philadelphia an obvious destination choice. Imagine adding Paul George to the young 76ers’ core until?

3. LeBron James Isn’t Getting Younger

James is currently attempting to reach the NBA Finals for an eighth straight time. If the Toronto Raptors don’t end that streak in the second Eastern Conference semifinals series, then it will eventually end at the hands of either the 76ers or the Celtics. James has to play at an all-world pace just to carry his team into the second round of the playoffs. The Cavaliers won’t be able to make dramatic roster moves again. As is, the Cavs are slow, which will make it difficult to keep up with Boston and Philadelphia going forward.