For a long time, the madness didn't extend to the No. 16 line.

Every No. 1 seed prevailed in this matchup through 2017. Sure, there were big-time scares -- top-seeded Georgetown scraping by Princeton, 50-49, in 1989; Oklahoma outlasting East Tennessee State 72-71 that same season; Michigan State surviving Murray State in overtime the following year -- but no basketball giant had to deal with the embarrassment of getting victimized by a No. 16.

Lightning struck twice, five years apart.

UMBC dominated Virginia in 2018, winning 74-54; undersized FDU ambushed Zach Edey-led Purdue last March, 63-58.

Could 2024 bring another No. 16-over-No. 1 stunner? 

Well, Edey and Purdue are back as No. 1 seeds, this time facing the Montana State-Grambling State winner in the Midwest Region. Let's dive into each No. 1-vs.-No. 16 matchup and isolate the best chance for a monumental takedown.

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16 vs. 1 upset rankings

Ordered from least likely to most likely.

4. Stetson over UConn

The Hatters feature a star guard in junior Jalen Blackmon. He's coming off a 43-point outburst in the ASUN Championship, a 94-91 win that sent Stetson to its first NCAA Tournament. But with Stetson ranking 342nd in defensive efficiency, the Hatters have zero chance of hanging with the defending champs. Last year, a similarly talented UConn team seeded fourth opened the NCAA Tournament with a 24-point pounding of Iona.   

3. Longwood over Houston

Longwood got hot at the right time. The Lancers won four straight -- three as underdogs --  in a thrilling run to the Big South Tournament title. Now, this 13-loss team faces an impossible test against Houston's stifling defense (56.9 ppg, 38.3 percent shooting allowed). This is a complete mismatch, nearly as lopsided as UConn vs. Stetson.  

2. Wagner/Howard over North Carolina

These No. 16 seeds went a combined 34-31 and likely pose no threat to the uber-talented and experienced Tar Heels.

Howard has the better chance of keeping this matchup interesting for a while, as the Bison shoot 37.5 percent from beyond the arc (19th nationally). In winning the MEAC Tournament, Howard shot 41.3 percent from deep. Howard also grabs an offensive rebound on 31.3 percent of its misses, which ranks 60th nationally.

In the end, though, look for UNC (81.5 ppg) to outscore either No. 16 seed by about 20.

1. Montana State/Grambling State over Purdue

Once they get past Grambling State, the Big Sky-champion Bobcats have the ingredients to give Purdue a scare. Montana State senior point guard Robert Ford III is a gritty leader, the conference Defensive Player of the Year, and he was an easy choice for Big Sky Tournament MVP. In the final against archrival Montana, Ford had 22 points, nine rebounds, five steals and four assists.

The Bobcats shoot 36.4 percent from deep (44th nationally). Though they have a first-year coach, they are in the NCAA Tournament for the third straight season. Ford is the kind of player who elevates his teammates. Standing just six feet, he led the team with 7.6 rebounds per game to go with his 15.9 points and 2.9 steals.

This is, however, a much better Purdue team than last season.

While the Boilermakers should — and probably will — advance comfortably, you can't ignore Matt Painter's NCAA Tournament record when compiling a ranking like this.