Which could happen with or without expanding the tournament. (I’m borrowing this from Bill Connolly of ESPN). One of the criticisms of the NCAAT is that the big boys lock down the vast majority of at-large bids and the midmajors are largely excluded.
First, and intriguing to me, is the coefficient concept. European soccer assigns spots in the Champions League and Europa League based on how teams from each country have performed in recent years. The countries that have done better, get more spots, which means a lot for Spain and England and not many for Greece or Sweden.
You could do the same in the NCAA. If a conference does surprisingly well year to year (say the Ivy with Princeton in the Sweet 16, or the MAAC with Saint Peter’s last year), or over a period of several years, reward them with an extra automatic bid. If several teams in a league do well, they might get three AQ spots.
You could do coefficients per individual conference, or you could do clusters. The worst 8 leagues over a 3- or 5-year period get nothing extra; the next 8 leagues get one extra bid among them; the next eight get two or three extra bids, and the top 8 are gonna get a lot of bids anyway, so it doesn’t matter.
Or you could base it solely on last year, with any league that won at least one game getting an extra bid (including the Ivy and NEC for next year). Or divide up the first 32 at-large solely on how many leagues won games.
You could also devise similar criteria for an expanded field, so that the extra 16 or 32 teams aren’t solely North Carolina or Vandy or Michigan. Those three would be in, true, but so would North Texas and UAB and Liberty. Connolly drew up a hypothetical 96-team field this year which would have had multiple bids for 22 of the 32 conferences while still getting 45 spots for the top seven leagues (B1G, SEC, ACC, Big 12, Pac-12, Big East and Mountain West).