NEW YORK — What is unusual about Sunday’s Christmas Day matchup between the Celtics and Knicks is that it carries significance for both teams.
If you recall, these two apparent rivals met last January, with splendid rookie Kristaps Porzingis scoring 26 points as New York beat the Celtics to improve to 20-20 and drop Boston to 19-19.
The Knicks were thinking playoffs. They were thinking a return to respectability. They were thinking second place in the Atlantic Division.
After Jan. 12, the Knicks went 12-30, and the Celtics went 29-15. The Knicks returned to the lottery, only to miss out on the draft because that pick went to the Nuggets, New York’s final balloon payment from the Carmelo Anthony trade.
The Celtics were in the lottery, too, by virtue of their franchise-boosting Paul Pierce-Kevin Garnett trade that garnered them three first-round picks from the Nets and the right to swap another. They chose Jaylen Brown No. 3 overall to enhance their improving roster.
This season, the Knicks trail the Celtics by a half-game as they scrap to approach first-place Toronto in the Atlantic Division. The Celtics and Knicks are rivals, but this really hasn’t been a rivalry for years.
These teams are considered the NBA’s original model franchises and they clashed for Eastern supremacy in the 1950s, ’60s and ’70s, with the Knicks knocking off the 68-win Celtics with an injured John Havlicek in the 1973 Eastern Conference finals en route to their most recent championship.
That was 43 years ago. Future Hall of Famers filled both rosters. The teams played in storied arenas. The cities held disdain for each other, and while that hatred still exists at Gillette Stadium and on the baseball diamond, the Celtics-Knicks rivalry has dissolved.
When the Celtics flourished in the 1980s, who were their primary rivals? The 76ers. When the Knicks made championship runs in the mid-1990s, who were their primary competitors? The Pacers and Heat.
The reason this matchup has lost its intrigue is the teams have seldom flourished at the same time. Last season, the Knicks were expected to push the Celtics in the Atlantic before their freefall. This season, Knicks president Phil Jackson traded for former league MVP Derrick Rose, signed aging center Joakim Noah, a teammate of Celtics forward Al Horford at the University of Florida, and added former Celtic Courtney Lee and Brandon Jennings to join Anthony and Porzingis.
The result has been inconsistency, but also enough success to become a playoff contender. Meanwhile, the Celtics continued their methodical rebuild by signing Horford to a four-year, maximum contract. The Celtics’ ascension has occurred because president of basketball operations Danny Ainge decided to strip the organization by moving Pierce and Garnett for draft picks, something the Celtics’ faithful understood because the Big Three couldn’t last forever.
The Knicks have taken a different approach, much to their detriment. Because it is New York, Knicks current (Jackson) and previous management believed it would be a premium free agent destination.
The Celtics don’t know how that feels, because of the franchise’s history of having to trade for or draft their premium players. Until Horford signed with the Celtics, Boston was only attractive to free agents who wanted to play for Doc Rivers.
The Knicks scored big with the drafting of Porzingis, Jackson’s most astute move in his rocky tenure as president. But they haven’t been able to use the draft to rebuild because of trades that gutted their first-rounders or moves such as the Anthony deal, which cost them Danilo Gallinari and Wilson Chandler.
What’s more, the last Knicks draft pick to make an All-Star team as a Knick was Mark Jackson in 1989-90. So their primary means of building and remaining competitive has been free agency, which in today’s NBA is a risky proposition, especially when major chips such as LeBron James and LaMarcus Aldridge, or lesser ones such as Greg Monroe, choose other teams.
Although they are improved, it’s inaccurate to call the Knicks a team on the rise. Anthony is 32. Lee is 31. Rose is a hard 28. Noah is a declining 31. Eventually New York is going to have to surround the 21-year-old Porzingis with other young and emerging talent, and prepare for Anthony to take a lesser role.
Until then, they are a potential playoff team, perhaps good enough to reach the second round, but hardly skilled enough to compete with Cleveland or Toronto. The Celtics, on the other hand, have built through the draft and free agency, are considerably younger, and have hopes of pushing the Cavaliers and Raptors.
But on this day they are just about even, separated by a half-game. And because the teams are geographically close, it is considered a rivalry. But it’s been 43 years since this matchup has meant something considerable to both teams. They are franchises with distinct philosophies heading in different directions.
For now, they intersect, and the collision should make for an entertaining Christmas Day matchup.
Gary Washburn can be reached at gwashburn@globe.com. Follow him on Twitter @GwashburnGlobe.
