It's been 21 years since they last met in a playoff series, and even that was a first-round sweep by a Rangers team headed for the Stanley Cup over an Islanders team that finished the season with a .500 record. The Rangers and Islanders have almost never been good at the same time.
Now, it seems, they are.
No wonder Rangers coach Alain Vigneault has labeled Tuesday night's meeting at Madison Square Garden as "a New York classic."
The Rangers have won 13 of their last 14 games (even if one Islanders player referred to it Tuesday morning as 14 of 15). The Islanders are in first place in the Metropolitan Division, five points ahead of the fourth-place Rangers (who have played three fewer games).
For just the second time in the Islanders' 43-year history and the first time since the 1978-79 season, both teams have 50-plus points in the first half of the season.
"This isn't even the halfway point in the season for us, but it feels like these two points are huge," Rangers captain Ryan McDonagh said.
For all the winning they've done lately, the Rangers haven't been able to pass the teams ahead of them. They have gained ground on the Islanders and the Pittsburgh Penguins, but those two teams and the third-place Washington Capitals have stayed in front.
Meanwhile, the Islanders talk of trying to create some separation in the standings, something they haven't been able to do, despite going 9-3-1 in their last 13 games and equaling a franchise record with 28 wins in the first 42 games of the season.
One of those wins came at the Garden, a 6-3 triumph in the first week of the season, when the Rangers were settling into the soul-searching stage that characterized their first couple of months.
"They're a different team now," Islanders coach Jack Capuano said Tuesday. "They found their swagger, their attitude, their chemistry."
They've found their defense, allowing just 22 goals in their 14-game surge. They've found their power play, scoring 10 man-advantage goals in the last eight games.
The 13 wins in 14 games are the best stretch any Rangers team has had in 42 years.
"I don't think we're thinking about it in historical terms," Carl Hagelin said. "We're just trying to win every game. But I know we're doing something special."
How special it is won't be determined until the spring, in much bigger games than the one they're playing Tuesday. But already, this game has the feel of being for something more than just bragging rights.
"It's going to be a fun 60 minutes of hockey for the fans," Derek Stepan said. "And great for our team. Since I've been here, when we've played the Islanders, we seem to put our best games out there against each other."
Well, except for the Rangers' performance in that game in mid-October.
"The rivalry's been great since I've been here," Stepan said.
If the Rangers and Islanders can both keep playing the way they have recently, it can only get greater.