CHICAGO — The puck drops Thursday as the Frozen Four begins.

Harvard takes on Minnesota-Duluth at 6 p.m. ET, followed by Denver vs. Notre Dame for the second spot in the championship game.

Before the action, let’s take a look back at how each team earned a trip to Chicago.

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Denver (31-7-4)

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DI Men's Hockey: Denver advances to Frozen Four

The Pioneers travel to Chicago with an NCAA-best 31 wins this season, which marks their highest total since the 2004-05 season when they took home the title. Led by Jim Montgomery, who was honored with the Spencer Penrose Award as college hockey’s national coach of the year, Denver was crowned NCHC regular season champs for the first time since 2010.

The Pioneers are led by Hobey Baker finalist and team captain Will Butcher, who has 36 points this season, placing him second in the nation in points by a defenseman.

After disappointment in the NCHC tournament, where Denver fel to North Dakota 1-0, the Pioneers bounced back to earn a spot in the Frozen Four. Playing in the Cincinnati region, Denver won its first round game against Michigan Tech 5-2 behind four goals in the opening period. The Pioneers then took down a high-scoring Penn State team in the second round, winning 6-3.

Minnesota Duluth (27-6-7)

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DI Men's Hockey: Minnesota Duluth skates to the Frozen Four

Minnesota Duluth returns to the Frozen Four after missing out the last five seasons. The Bulldogs will meet up with Harvard for the 14th time, and the first time in over 21 years.

“I think they're very balanced. Obviously, they've got some very talented forwards up front. Their top two lines especially. There's a lot of skill, a lot of deception. They're a puck-possession team. I've been impressed with their poise and composure,” coach Scott Sandelin said about Harvard at Wednesday’s press conference.

The Bulldogs had a close call in the first round of playoff action when they faced Ohio State in Fargo. Despite taking a 2-0 lead in the second period, the Bulldogs allowed two goals in the third to tie it up. A goal in overtime from Willie Raskob advanced Minnesota-Duluth to the second round where they faced Boston University.

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Overtime was again needed in that second round game. BU and UMD were even throughout the game, but a power play goal from Adam Johnson gave the Bulldogs a 3-2 win and a chance to play in the Frozen Four.

Harvard (28-5-2)

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DI Men's Hockey: Harvard advances to Frozen Four

Harvard’s last Frozen Four appearance was in 1994. That drought comes to an end with the Crimson making their way to Chicago after taking the Beanpot title and the ECAC championship.

"I think they're a very impressive team. I think they're extremely well coached. I think they have great balance. When you think of such a storied college hockey program and you think with all the great players and the great teams they've had, and to think this is the team with the least amount of losses, it's really quite impressive," Harvard head coach Ted Donato said about Minnesota-Duluth on Wednesday. 

The Crimson topped Providence at the Dunkin Donuts Center in the first round, winning 3-0. Harvard faced off against Air Force in their next game. The Crimson got off to a hot start, leading 3-0 through the first half of a game. Air Force tallied two goals later in the second period to make things interesting, but the Crimson fended off Air Force, allowing no goals in the third period.

In goal for the Crimson is Merrick Madsen, who was named the East Region’s most outstanding player. In the first round game with the Friars, Madsen stopped all 41 shots he faced, which was a new career high, earning himself his third shutout of the year.

Notre Dame (23-11-5)

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DI Men's Hockey: Notre Dame advances to Frozen Four

The Fighting Irish are the only team headed to the Frozen Four who were not a top seed in their region. This trip to the Frozen Four marks the third time in program history, as Notre Dame was in the championship in 2008 and the semifinals in 2011.

Notre Dame fell to UMass Lowell in the Hockey East semifinals but made it into NCAA tournament regional play. The Fighting Irish defeated No. 1 seed Minnesota 3-2 back on March 25 in New Hampshire thanks to a go-ahead goal from Andres Bjork in the third period to earn a spot in the next round.

Then having to face UMass Lowell again, Notre Dame came out on top this time when Andrew Oglevie scored with 2:44 in the first overtime period. Bjork, who tallied three points in the game, was named the Northeast Regional’s most outstanding player.