Though U.S. colleges had been fielding men's ice hockey teams since 1895,[1] the NCAA did not have a formal tournament in place to decide a champion until after World War II.
For the 1981 tournament the NCAA altered the rule to guarantee a full quarterfinal round and started including true 'at large' teams for the first time.
With 4 major conferences and a myriad of independent programs competing at the Division I level, the tournament was expanded to 12 teams beginning with the 1987-88 season.
The first round followed the same pattern as the quarterfinals with teams playing two games against a single opponent and the one with a higher goal total after the series advancing.
After the addition of two more conferences around the turn of the century (MAAC and CHA, neither of which now sponsors men's hockey) bringing up the total number to 6, and with each receiving an at-large bid starting in 2001 and 2003 respectively, the tournament was again expanded by 4 teams.
Penn State's rise to the D-I ranks gave the Big Ten its sixth university that sponsored varsity men's ice hockey, a number significant for two reasons.
In response several members of the WCHA, including traditional powerhouses Denver and North Dakota, split to form a new conference, the NCHC.
However, the shift did create one more automatic qualifier for the tournament, reducing the chance to receive an at-large bid for all schools across the nation.