Miami was selected as the top seed for the 64-team Division I college baseball tournament Monday, two-time defending champion Oregon State was left out of the field and the Big 12 Conference officially learned that six league schools had qualified for the postseason.

Missouri, Nebraska, Oklahoma, Oklahoma State, Texas A&M and conference tournament champion Texas each learned of their regional destinations Monday.

Nebraska, Texas A&M and Oklahoma State are hosting regionals at their home fields.

Miami (47-8), who won the Atlantic Coast Conference tournament for the first time, will host one of 16 four-team, double-elimination regionals that begin Friday. Miami, making its 36th straight tournament appearance to extend its NCAA record, was ranked No. 1 in various polls for the majority of the season.

“There was a lot of discussion about who the No. 1 seed should be, and quite frankly, North Carolina and Arizona State all got a strong look at that position,” selection committee chairman Larry Templeton said. “Miami’s play toward the end of the season, particularly winning the tournament – and we were watching that tournament as the selection process was going through – convinced (us).”

The other national seeds, in order, are: North Carolina (46-12), Arizona State (45-11), Florida State (48-10), Cal State Fullerton (37-19), Rice (42-13), LSU (43-16-1) and Georgia (35-21-1).

The winners of each regional will advance to the super regionals, played June 6-9. The eight winners of the super regionals will play in the College World Series, which starts June 14 in Omaha, Neb.

Being the top seed hasn’t necessarily guaranteed tournament success. The only No. 1 overall seed to win the College World Series since the field was expanded to 64 teams was the 1999 Hurricanes, and no top-eight seed has won it all since Rice in 2003.

Oregon State (28-24) did not receive an at-large bid, despite having five series wins against teams in the 64-team field, including Arizona, Arizona State and Georgia. The Beavers, the first defending champ to not make the tournament since Georgia in 1991, will not have a chance to join Southern California (1970-74) as the only schools to win three straight titles.

“The committee struggled long and hard and, quite frankly, probably wouldn’t have struggled as long if Oregon State had not been the two-time defending national champion,” said Templeton, also the athletic director at Mississippi State. “The thing that probably was the determining factor was their 24 losses and who some of those losses were against. It was a tough call, but we felt that there were a couple teams more deserving.”