Taking a detailed look at the state of the bracket right now, just over the halfway point in the season:
- Are there any locks yet? Depends on how you define "lock". If a lock is a team that has a good enough resume to make the bracket even if they lose out going into the tournament, then there's really only one stone-cold lock right now: Auburn. Gonzaga is close, but losing out would probably provide too many bad losses with the teams left on their schedule.
- If you define lock as "statistically certain to make it", since losing out is basically statistically irrelevant for teams of that quality, then there are an additional 18 teams that are statistical locks: Arizona, Baylor, Duke, Gonzaga, Houston, Illinois, Kansas, Kentucky, LSU, Michigan State, Providence, Purdue, Tennessee, Texas Tech, UCLA, Villanova, Wisconsin, and Xavier
- Another 17 teams aren't quite locks, but they should be safely in at this point in their schedules (80% likely or better): Alabama, Arkansas, Boise State, BYU, Connecticut, Indiana, Iowa, Iowa State, Marquette, Murray State, North Carolina, Ohio State, San Diego State, St. Mary's, TCU, Texas, USC
- 20 conferences don't have an at-large shot, and will be one bid leagues for sure, with an additional 2 conferences that have bubble teams that could steal a bid (MVC (Loyola) and A-10 (Davidson) ).
- That leaves 10 to 12 bids for bubble teams, with 20 teams currently having a 5% or better chance to make the tournament: Belmont, Colorado State, Creighton, Davidson, Dayton, Florida, Loyola Chicago, Miami-FL, Michigan, Mississippi State, Notre Dame, Oklahoma, Oregon, San Francisco, Seton Hall, SMU, St. Louis, UAB, Wake Forest, Wyoming
Beyond that, there are other teams out there who can play themselves into at large contention, like West Virginia or Virginia Tech, but it's a huge uphill climb at this point.
For the B1G, that likely means 8 bids max unless one of Rutgers-NW-Maryland-PSU gets really hot and takes that automatic bid, which could inadvertently hurt Michigan's bid chances anyway.
As to where that leaves Illinois at this point, their metrics have them as a 4 seed, and their results profile also has them at a 4 seed at this point, so they seem safely lodged there for the time being as long as they remain on their current trajectory.