PITTSBURGH — Eighteen teams in college hockey have won the Division I men’s championship. That’s about to change.

Over the past two decades, the traditional powerhouses have dominated DI college hockey. In 2011, Minnesota-Duluth became the 18th team on the list of Frozen Four champions and the first new addition since 1993.

But this year the big name teams — Denver, North Dakota, Wisconsin, Boston College, Boston University and Minnesota — are conspicuously absent from the bracket. Nine-time champion Michigan, the most decorated school in DI hockey, did not advance to the tournament for the first time in 22 years.

Beginning Thursday afternoon, Yale, UMass-Lowell, Quinnipiac and St. Cloud State will jockey to become the 19th name on the list of Frozen Four champions.

“It really sets parity throughout Division I,” said Joseph Pendenza, a forward for UMass-Lowell. “It might be weird to the average observer because they might not be used to these names. But I think you look a little closer, and it says just how close every team is throughout the country.”

Parity is likely a word on the minds of many players, coaches and fans in this Frozen Four. Both semifinal matchups will pit regional No. 1 seeds against No. 4 seeds, but the consensus is that anyone could take the title.

Quinnipiac enters the tournament as the top seed after leading the national rankings for most of the season. UMass-Lowell finished third in the polls, St. Cloud came in at ninth and Yale took 15th. Then St. Cloud upset Notre Dame and Miami of Ohio in the Midwest Regional, and Yale shocked the nation with successive wins against Minnesota and North Dakota in the West Regional.

“I think any team here can win it,” Yale head coach Keith Allain ’80 said. “I like our chances.”

Yale is the only team of the four that has made a previous Frozen Four appearance and that was in 1952, when a gallon of gas cost 20 cents and the average price of a house was $228. Back then the tournament consisted of a four-team bracket chosen by an NCAA committee. Two teams were selected from the east conference and two teams from the west.

The committee’s custom was to choose the strongest Boston team and the winner of the Pentagonal League, the forebear of the Ivy League, but the rise of schools outside of those two traditional bastions complicated the selection in 1952. That year, the NCAA controversially selected St. Lawrence, in addition to the Pentagonal Champion Elis, instead of either Boston College or Boston University.

Pat Howe ’52, a right-winger on the 1952 squad, said when he was playing there was “a lot of very close competition” between the eastern schools. The selection process for the DI tournament was not at all clear-cut, he recalled, and the committee struggled to determine the qualifiers based on records alone.

“I think it was not black and white — they had to put a lot of personal opinions into it,” Howe said. “There were a lot of judgment calls in selecting Yale as the winner. There were a lot of contentious comments as in ‘why should Yale be picked’ and so on.”

Since then, the tournament bracket has expanded steadily — most recently growing from 12 to 16 teams in 2001. The winners of each of the five D1 conferences automatically get a bid, and then the next 11 teams are chosen based on a mathematical formula, approximated by the PairWise Rankings.

Yale slipped into this year’s bracket after Notre Dame knocked out Michigan in the Central Collegiate Hockey Association final, making the Elis the last team to qualify for the tournament.

When the Bulldogs take the ice Thursday afternoon, at least one member of the 1952 team will be in the stands watching. Mike Robinson ’52, a former defenseman whose brother lives in Pittsburgh, said he is making the trip to watch the current Yale squad take on UMass-Lowell at the CONSOL Energy Center.

Howe, who lives in Connecticut and attends a few hockey games each year, said he has followed the team’s progress and figured it was only a matter of time before Yale made another Frozen Four appearance.

“They have a good coach and a good recruiting program,” he said. “Yale I think has earned its position in the past few years.”