code in each cell represents the furthest the team made it in the respective tournament: Team played in a District tournament, but did not win it (1954–1974). Team was the district representative but did not reach the College World Series (1947–1949). Team advanced to the College World Series, but was not one of the top two teams. National Runner-up National Champion 1975–1998 From 1975 through 1998, the NCAA tournament consisted of eight regionals, the winners of each advanced to the College World Series. However, unlike previous tournaments, there was no requirement that the regions consist of an exact set of states. The code in each cell represents the furthest the team made it in the respective tournament: Team was selected for a Regional, but did not win it. Team advanced to the College World Series, but was not one of the top two teams. National Runner-up National Champion Starting in 1982, the NCAA identified 5 teams as national seeds and ensured they played in different regionals. Starting in 1987, the NCAA identified the top 8 national seeds and put them in different regionals. These national seeds are shown with . These national seeds often hosted the Regional round, but not at the near-automatic rate of hosting in the modern NCAA Tournament. 1999–present Starting in 1999, the NCAA expanded to a 64-team format with 16 regionals seeded 1 through 4. The code in each cell represents the furthest the team made it in the respective tournament: Team was selected for a Regional, but did not win it. Team won their Regional and advanced to the Super Regional round, but did not win it. Team advanced to the College World Series, but was not one of the top two teams. National Runner-up National Champion Additionally, the top 8 national seeds are shown with , and the other eight 1 seeds are shown with . These are usually, but not always, the 16 teams hosting in the Regional round. Past formats 1947 The first tournament was an 8 team single elimination tournament. Four teams each were put into two playoff brackets, named the "Eastern playoff" and the "Western playoff." The winner of each bracket moved on to the College World Series, which was, at that time, a 2 team best-of-three-game series. 1948 The second year of the tournament maintained the "Eastern playoff" and "Western playoff" format, however, they were now double elimination. The