OMAHA, Neb. -- As good as the record-setting Vanderbilt baseball team has been this season, North Carolina has been just a little bit better.
That was the opinion of the NCAA Division I baseball tournament selection committee, which on Monday picked the Tar Heels as the No. 1 national seed for the 64-team tournament.
"It was really a close, close call," committee chairman Dennis Farrell said. "I'm not so sure I can really articulate what the determining factor was."
The tournament opens Friday with 16 four-team, double-elimination regionals. Best-of-three super regionals will be held next week, with those winners moving to the College World Series in Omaha.
The national seeds behind North Carolina and Vanderbilt, in order, are: Oregon State, LSU, Cal State Fullerton, Virginia, Florida State and Oregon.
North Carolina (52-8) won its first ACC regular-season championship since 1990, and its 48 regular-season victories were a school record. The Tar Heels lost two straight series to end the regular season, but they remain the only team in the nation that hasn't lost consecutive games.
In the ACC tournament they needed 14 innings to beat Clemson and 18 to defeat North Carolina State before they won the title with a 4-1 victory over Virginia Tech on Sunday.
They're averaging 8.2 runs a game, and their .867 winning percentage is the best in the country. They have the conference pitcher and player of the year in left-hander Kent Emanuel and third baseman Colin Moran.
The No. 1 seed is a first for coach Mike Fox's program. The Tar Heels have been a top-eight seed six of the last seven years.
"It's exciting," Fox said. "It's just important to be one of the top eight, really. Just try to be a national seed, so if you're fortunate enough to win a regional, you know you're playing at home the next weekend."
The Tar Heels open against Canisius (42-15), which is in the tournament for the first time after winning the MAAC postseason title.
"It's about preparing for the next phase of our season," Fox said. "After that first pitch Friday, the seeding doesn't come into play."
Vanderbilt (51-9) looked to have a good shot at earning the No. 1 seed after winning a record 26 regular-season games in Southeastern Conference play. The Commodores feature pitcher Tyler Beede, who is unbeaten in 14 decisions.
Vanderbilt had the nation's No. 1 RPI after the regular season, ahead of North Carolina. That was just one of the criteria used by the selection committee, Farrell said.
"It really is kind of a marriage of art and science," he said. "We get a lot of data put in front of us. We get advice from regional advisory committees. At the end of the day it's a vote of 10 committee members."
Farrell said the decision to pick the Tar Heels over the Commodores was made before the end of Vanderbilt's 5-4, 11-inning loss to LSU in the SEC tournament championship game Sunday.
For Vandy's sake, maybe it's just as well it didn't get top billing. The 1999 Miami Hurricanes are the only top-seeded team to go on to win the national title, and that was in the first year of the current tournament format.
The SEC led all conferences with a record-tying nine bids. The ACC has eight, and the Pac-12 and Sun Belt have four apiece.
Arizona (34-21) won't get a chance to defend its national title. The Wildcats were left out of the tournament for the first time in four years despite winning five of their last six to finish 15-15 in Pac-12 play.
Miami (36-23) is in the tournament field for the 41st straight year, extending its own record.
Along with Canisius, first-time participants will be Bryant, Central Arkansas, Savannah State and South Dakota State. Bryant, from Smithfield, R.I., made it in its first year of eligibility since moving from Division II.
Thirty-one of the 64 teams were in the field last year.
Colonial Athletic Association postseason champion Towson (29-28) is sure to be one of the tournament's top stories. The Towson baseball and men's soccer programs were destined to be cut because of athletic department financial problems and gender-equity imbalance. The baseball program was given a reprieve thanks to an injection of $300,000 a year for two years in state funding approved in April. Soccer was not saved.
San Diego and San Diego State qualified for the tournament in the same year for the first time. That extends a prolific season for slugger Kris Bryant, who has hit a nation-leading 31 homers for San Diego.
Bowling Green (24-29) is the only team in the field with a losing record. The Falcons won the Mid-America Conference tournament and are in the national tournament for the first time since 1999.
Farrell said Mercer (43-16) was the last at-large team picked. Michigan State (33-17), which didn't qualify for the Big Ten tournament but had a No. 36 RPI after the regular season, was the first team out.