(CNN) This NBA Finals is in uncharted territory.
For the third consecutive year, the Cleveland Cavaliers and Golden State Warriors are facing off with the title on the line. The Cavaliers, who in 2016 ended a sports title drought the city of Cleveland had been living under since 1964, are aiming to repeat. The Warriors, who won the title in 2015, are out for revenge.
This is the first time in NBA history that the same two teams are meeting in the NBA Finals for three straight seasons. To take it further, never has there been a championship "rubber match" -- the third installment between two teams that would break the tie -- in any other North American professional team sport. Until now.
This trilogy, which is scheduled to end in mid-June, will leave either Golden State or Cleveland with bragging rights.
"It's definitely unique," Cavaliers head coach Tyronn Lue said. "It's nothing you can take for granted. Even though we have the best player in the world (LeBron James) on our team, you still can't take it for granted. Health plays a part, a lot of things play a part in this. So going to The Finals three straight years, you have to enjoy it. You have to relish the moment.
"But now that we are here, we have business to take care of."
How rare is it for the same two teams to meet three years in a row with a championship on the line? It's only happened once in each of the other major North American professional sports -- and the last instance was more than half a century ago, when the Detroit Red Wings and Montreal Canadiens battled for the Stanley Cup from 1954-1956. The Red Wings won the first two Cups, while Montreal hoisted the third.
In the NFL -- before the Super Bowl era began -- the Detroit Lions topped the Cleveland Browns in 1952 and 1953, with the Browns getting retribution in 1954.
You have to go back even further for a Major League Baseball trilogy, and it all took place in New York City. The New York Giants got the best of the New York Yankees in back-to-back seasons, winning the World Series in 1921 and 1922.
But in 1923, the Yankees, playing their home games in the original, brand-new Yankee Stadium, got the best of the Giants, winning the World Series in six games. That Yankees' roster was packed with Hall of Famers Babe Ruth, Lou Gehrig, Waite Hoyt and Herb Pennock.
Which brings this back to present day. Unbelievably, this already-loaded Warriors' roster from last year -- led by Stephen Curry, Klay Thompson and Draymond Green -- got better by adding superstar Kevin Durant. He's seeking his first title and is second for the Warriors in scoring with 25.2 points per game this postseason.
"I can't go out there and do everything on my own, or I can't go out there and just let my teammates do all the work for me," Durant said. "I got to do my part and we all got to make it come together as a group."