The post-season Division 1 baseball tournament involves a field of 64 teams with 31 teams being awarded automatic bids for winning conference titles. Six of these automatic bids typically come from power baseball conferences. These teams are often 1 seeds. The remaining 25 automatic conference championship bids are typically 3 or 4 seeds.
If a team is not a conference champion, then they’re competing for the remaining 33 invited at-large spots. That’s where the RPI or Ratings Percentage Index comes into play. The most powerful conferences send multiple runner-up at-large teams to the tournament. These at-large teams are typically high RPI ranked teams and are often slated at 2 or 3 seeds.
In inviting the 33-at large teams to the 64-team field in the post-season tournament, the selection committee uses the following criteria:
- Overall record
- Division 1 record
- Overall RPI Ranking (Teams with an RPI ranking of 45 or above have a chance at making the cut for an at-large selection if they are from a baseball power conference. Any team with an RPI ranking higher than 32 is virtually assured an invitation.)
- Non-conference record and RPI rank
- Conference regular-season record and conference tournament results
- Road record and RPI
- Last 15 games’ record
- Record against teams ranked 1-25, 26-50, 51-100, 101-150 and below 150 in the RPI
- Head-to-head record (record against other potential invitees to the tournament)
- Common opponents’ record (same as in #9)
As you can see, the RPI ranking is an important but controversial metric used in the tournament selection process and appears in 4 of the 10 criteria employed by the selection committee. The information is presented to the committee in a tabular format known as the “nitty gritty report”.
The 16 regional host sites consist of the 8 national seeds (teams that are very high in the above 10 criteria) and the next best 8. These teams include the power conference champions and other high level performers and are presented on the day before the remaining members of the 64-team field are announced.
