The new bubble: How NCAA Tournament expansion impacts seeding, March Madness bids

The NCAA Tournament continues to move toward expansion from a 68-team field to a 76-team field, adding eight at-large bids to the mix. The expected move would serve as the largest adjustment to seeding, historic matchup data, and bubble format since the expanding from 53 to 64 in 1985.

Under the new guidelines, the ‘First Four’ games in Dayton, Ohio will expand to a mini first round in at least two locations with 12 games across Tuesday and Wednesday. Six of those games will feature the final 12 teams in the field as at-large candidates, with 12 more automatic bids battling for spots on the 15-seed and 16-seed line.

Beside the massive format change, the perception of March Madness matchups will have to shift. Here is a look at how the NCAA Tournament bubble will shift in 2027 and beyond.

The new bubble debate

The NCAA Tournament expanded to 68 teams in 2011, adding the ‘First Four’ matchups to the mix. While it changes how many teams made it into the March Madness mix, it did not significantly shift where the bubble sits thanks to the play-in format. What did shift it down the board two spots, in theory, is the addition of 16-seed play-in games.

Regardless of how many spots make up the NCAA Tournament, the first step is to fill out automatic bids. With the return of the Pac-12, and a restructuring move by the ASUN and WAC to form the United Athletic Conference, 32 teams will secure their spot with a conference tournament title.

That means the number of at-large bids will leap from 37 in 2026 to 44 in 2027. Because the NCAA Tournament field will shift from two 16-seeds going through the play-in to four 16-seeds and two 15-seeds, it pushes the bubble well down from its current spot.

Just two years after both at-large ‘First Four’ games were played on the 10-seed line, there will almost certainly be a play-in game — or up to four — on the 12-seed line. As always, the exact place in the bracket will be determined by how many of the automatic qualifiers land above the cutline for at-large teams — a calculation complicated by Gonzaga’s departure from the WCC.

The shift that can be guaranteed is the perception of the famous 5-seed vs. 12-seed matchup, along with the less-talked-about 4-seed vs. 13-seed matchup. Those teams previously in position to pull off an upset will now face a Top 16 overall seed, setting up more debate over a chalky first round.

Only time will tell whether these mid-major teams can carry their success from the 5-12 game to the 4-13 game, but one of the greatest explanations for the phenomenon was the gap from the 4-seed line down to the 5-seed teams while the 12-seed teams often came into the postseason on win streaks with strong overall records.

Teams on the bubble

The new-look bubble will completely shift what the bracketology picture looks like throughout the season. The seven added teams from one season prior, along with an eighth via the Pac-12 Tournament, will open the door for widespread debate.

Missing the NCAA Tournament has already become a knock on the resume of many coaches, but a March Madness berth will only become more of a necessity. Every hotseat coach in college basketball needs to find their way into the picture.

Last season, the First Four Out featured Oklahoma, Auburn, SDSU and Indiana. In 2025 it was West Virginia, Indiana, Ohio State and Boise State.

Since 2021, the First Four Out has featured 21 different programs, with just seven outside the power conferences and Big East. During that span, Oklahoma (3) and Indiana (2) are the only programs to fall so close to the March Madness cutline multiple times.

By conference, the ACC, Big Ten, Big 12 and SEC all finished with four ‘First Four Out’ teams over that six-year stretch. The Mountain West also saw three teams in this category, with just one Big East school.

The NCAA does not released data on the ‘Next Four Out’ category which becomes the new bubble in a 76-team field. However, over the past two seasons, On3 placed Cincinnati (x2), Dayton, New Mexico, Seton Hall, UC Irvine, Virginia Tech and Wake Forest in that group.