The NIT features
a 32-team field chosen right after the NCAA chooses the 68 teams
in its tournament. It awards automatic bids to regular
season conference champions who do not otherwise go to the NCAA
tournament. Also, the first 4 teams out of the NCAA tournament
become automatic 1 seeds in the NIT.
The CBI features 16 teams and the CIT has 32 teams exclusively
from mid-major leagues or lower (only 26 teams participated in
2016 and 2017). The CIT requires teams to have a .500 record
or better while the NIT and CBI do not have such a
requirement. The CIT also doesn't place teams in a bracket,
opting to place teams in matchups after the previous round has
Schools have been known to decline an invitation to the CBI/CIT
tournaments due to the lack of interest in playing in a third-tier
tournament (e.g., "We're Indiana. We don't play in the CBI.") or
the pay-to-play nature of these tournaments.
The Vegas 16 was a 5-day
postseason tournament featuring 16 teams playing all games in Las
Vegas in the week leading up to the Final Four. The 2016 edition
only featured 8 teams in a 3-day tournament. It was cancelled for
2017 and it's unclear if it will be revived in 2018.
To get a feel for what kind of teams are involved, these were the
2017 participants along with their record and RPI.