In 16 of the past 22 NCAA Tournaments, at least one No. 13 seed has knocked off a No. 4 seed. It happened again last season when No. 13 Furman toppled No. 4 Virginia in dramatic fashion.

With 12 seconds left, the Cavaliers inbounded the ball with a two-point lead. All they had to do was advance the ball and wait to get fouled. But a Paladins trap led to an errant pass. Garrett Hein intercepted, fed JP Pegues, and the sophomore stepped confidently into the game-winning 3-pointer. Final score: Furman 68, Virginia 67.

UVA had closed as a 5.5-point favorite. It was an upset, but not a monumental one.

This year, every No. 4 seed is laying at least 7.5 points. So, which is the most vulnerable? Here are my rankings, from least likely No. 4 to go down to most likely.

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13 vs. 4 upset rankings

Ordered from least likely to most likely.

4. Yale over Auburn 

The Tigers rank in the top 10 in both offensive and defensive efficiency. Coming off their SEC Tournament championship, they had a strong case for a No. 3 seed. They don't lose to lower-tier teams either, going 24-0 against opponents from Quads 2, 3 and 4. Yale needed an 8-1 run in the last 23 seconds to defeat Cornell in the Ivy League final. The Bulldogs will acquit themselves well, but they're 0-3 against Quad-1 teams and will be overmatched here.

3. Charleston over Alabama 

As a No. 12 seed last year, the Cougars nearly upset San Diego State in the first round, falling 63-57 to a team that would advance to the national championship game. This year the Cougars started slow, but they enter the tourney on a 22-3 run. Charleston boasts good size and attacks the offensive glass, which could keep this interesting. Both teams love to play fast. Ultimately, Alabama should pull away thanks to its lethal offense.

2. Vermont over Duke

The Catamounts enter on a 10-game win streak after taking the America East Tournament for the fifth time in six seasons. They boast the 62nd-best defense, per KenPom, and that could slow down Duke's array of scorers. The Blue Devils, who come in on a two-game skid, have something to prove after exiting in a second-round loss to Tennessee last season.

1. Samford over Kansas

Without Hunter Dickinson and Kevin McCullar, the Jayhawks were blown out by Cincinnati in their first Big 12 Tournament game. Both stars are expected to be on the floor Thursday when Kansas faces surging Samford. How effective they'll be remains unclear.

This is a popular upset pick, and for good reason. Kansas has lost four of five and faces the best No. 13 seed in the tournament.

Samford, led by 6-9 junior Achor Achor (15.8 PPG, 6.1 RPG, 59.9 FG%), ranks seventh nationally in scoring (84.3), eighth in 3-point shooting percentage (39.3) and ninth in overall field-goal percentage (48.9). Money has poured in on Samford, both against the spread and on the money line, since betting lines opened.

This should be a tight game, and easily offers the best chance of yet another 13-over-4 upset.