Boston won all three when the teams squared off in 1962, '63 and '65. The Celtics repeated the feat three times in four years at the end of that decade.
So when the longtime rivals met in Game 7 last night, it was easy to consider it the end of a chapter but not the end of the story.
Yet there also was the feeling that the Celtics were making their last stand with their Big Three of Paul Pierce, Kevin Garnett and Ray Allen, which already was an older group when it was put together in the summer of 2007 - even before Garnett needed knee surgery that robbed him of some explosiveness.
"I hope not," coach Doc Rivers said. "Obviously, I'm not sure. I do think, and I've said this before, that I think we're going to be better in some ways next year because Kevin will be healthier, if you know what I'm saying. It's always a year removed from surgery that you have your best year."
Boston provided a blueprint for how to construct a champion in a hurry three summers ago when it acquired Allen and then Garnett in separate trades. Put the right mix of superstars together and a 24-win team can turn into a 66-victory powerhouse, as the Celtics did in 2007-08 in the greatest one-year turnaround in NBA history.
So what if Miami or Chicago or the Knicks can find a way to put LeBron James and Dwyane Wade, or one of them and Chris Bosh, or some other All-Star combination together this summer in free agency? "There's going to be a power shift," Hall of Famer Julius Erving said.
Allen could wind up on a team with one of them, a free agent who'd potentially be a nice complement to their athleticism with his outside shooting. But his focus now is still on being a Celtic, not beating the Celtics.
"That's something that I've never been a 'look too far in the future' type of person,'' Allen said, "because I've been with other great players and I've been on teams with other great coaches, and you just always take solace in the fact that you do everything you possibly can to get yourself in a good situation and move forward, whether it's in your current situation or if you have to move."
Yet when everything was settled, it was the Celtics beating both to set up a 12th championship meeting with the Lakers.
So perhaps this revival of the league's greatest champion will be a brief one, even if nobody in green last night would believe it.
"We don't talk about it at all, and I don't think this is, anyway," Rivers said during the series. "So we don't think that. I think everyone outside of us, a lot of people do."