(CNN)A word to describe this year's Stanley Cup playoffs: chaos.
For the first time, all four wild card teams advanced out of the first round and all division winners were knocked out. It also marked the first time that the top teams from each conference -- the Tampa Bay Lightning in the East and Calgary Flames in the West -- were eliminated in round one.
Left standing for the Stanley Cup Final are the Boston Bruins and St. Louis Blues, with the best-of-seven series beginning Monday in Boston. They last met in the Stanley Cup Final in 1970, when Boston's Bobby Orr flew through the air after scoring in overtime in Game 4 for the sweep.
In an iconic hockey photo, Bobby Orr dives into the air after scoring against the St. Louis Blues on May 10, 1970. The goal clinched the Stanley Cup for the Boston Bruins.
The Bruins, the third-best team from the regular season, are less of a surprise to get this far. The six-time champions are back in the final for the third time in the last nine postseasons, last winning in all in 2011. Their road to the finals had them defeating Toronto, Columbus and then Carolina to win the Eastern Conference.
"We've earned the right to be where we are, to go to the Stanley Cup Final," Bruins head coach Bruce Cassidy said. "We've beaten three good teams. There is some unfinished business, so that's part of the emotion that you want to keep in check. You want to enjoy it, but I think our guys understand there are still four more steps to take."
For the Blues, meanwhile, it's been a long wait, and their journey from worst to first -- in the same season -- is almost complete.
St. Louis fired head coach Mike Yeo and replaced him with Craig Berube in November. The team was at the bottom of the league on January 2. Now, after climbing up the NHL standings to finish 12th overall, the Blues are in the final. The Blues have never won the Stanley Cup, having been swept in their other appearances, which came three straight years from 1968-1970.
"Once we got going in January and February, I knew we had a good hockey team," Berube said. "We get in the playoffs, and anything can happen. You've got to get here, and we did. Credit to our players. They battled and they believed we were going to make the playoffs, and we made it, and now we're here."
The Blues are the 10th team to reach the Stanley Cup Final after ranking 12th place or lower during the regular season. Six of those instances have come since 2006, including three under the current playoff format. St. Louis advanced through the Western Conference playoffs with wins over Winnipeg, Dallas and San Jose.
Despite the nearly half century gap in ice hockey, the cities of St. Louis and Boston have a lengthy championship history. The Red Sox and Cardinals faced each other in the World Series in 1946, 1967, 2004 and 2013, while the Boston Celtics met in the NBA Finals against the St. Louis Hawks in 1957, 1958, 1960 and 1961.
And when the Rams were in St. Louis, the New England Patriots won their first Super Bowl, back in 2002.
In all, Boston has won seven of those 10 meetings.