Field of 64 · Who Makes the NCAA Tournament
The 2026 tournament is over, Omaha already crowned a champion. This page is our last pre-Selection-Monday field projection, kept as the record rather than updated live. It updates daily again once the 2027 committee season starts. For how the real bracket played out, see CWS Odds and the Omaha field-of-8 column.
How the projection is built
Three stages. A gradient-boosted classifier scores every D1 team's resume on Selection Day; the top 64 by probability is the projected field. A second model ranks that field for the top-16 national seeds. A constraint solver then assigns the 2/3/4 seeds to each regional under two rules: same-conference teams go in different regionals, and 3/4 seeds get placed by geography. Baseball America and D1Baseball maintain their own human-judged projections that we ingest each day for comparison.
Selection day is the Monday after the conference tournaments finish, once the real bracket lands, the McConnellMargin column is replaced by the actual NCAA field.
Accuracy on the historical record
On the eight years 2016-2024 (skipping the 2020 COVID year), leave-one-year-out testing puts the at-large model at a 76% hit rate (standard deviation 3.5 points). Best year 2018 at 81%, worst 2021 at 69%. Top-16 seed overlap averages 73%. Public bracketologists at Baseball America and D1Baseball hit around 85-90%, the ~10-point gap is the editorial layer (injuries, coach turnover, momentum, conference reputation) that the resume vector alone doesn't see.