The number next to Tennessee’s name in the NCAA tournament bracket, 11, makes the Volunteers look like heavy underdogs against Michigan on Friday night. How Tennessee got to the Sweet 16 makes it look like a serious upset threat.
Teams that are underseeded tend to outplay their seed, as I wrote last week. So do teams that have to play their way into the main tournament bracket, which I wrote about in a separate article. Yet most of these teams still lose their next game, when they face heavy favorites. Tennessee, thanks to a kind draw, is in the small group of teams that were underseeded, had to play their way in, and then won their next game. Similar teams went on to achieve major tournament success.
Ken Pomeroy’s ratings on Selection Sunday ranked Tennessee as the 13th best team in the country, worthy of a No. 4 seed. And the Volunteers have played like it since, winning their play-in game over Iowa by 13 points and then crushing UMass and Mercer by 19 and 20, respectively. No other team got to this year’s Sweet 16 with two wins as lopsided as Tennessee’s.
The Volunteer’s next opponent, Michigan, is the Midwest’s second seed and reached last year’s championship game. The Wolverines are favored over Tennessee by 2.5 or three points by Las Vegas sports books.
But teams like Tennessee have been dangerous at this stage. The Vols — by virtue of beating Iowa and playing their way into the tournament — joined a group that historically outperforms its pre-tournament level by two points per game. Those two points, however, usually aren’t enough against their next, higher-seeded opponents.
By beating UMass, Tennessee became just the 33rd play-in winner to win its next round (including in that group teams that had to win games in the early 1980s to advance and face a team that got a bye). How much these teams were underseeded is correlated (R>0.32) with three measures of later success: margin of victory in their next game, subsequent tournament wins and eventual finish. (The last two aren’t redundant because the tournament’s field size and number of rounds have changed.)
Underseeded Play-in Winners That Won Their Next Game
Five of the 32 teams before Tennessee were underseeded by four or more, according to their pretournament Simple Rating System ranking, as calculated by my colleague Benjamin Morris. (Pomeroy ratings don’t go back to the 1980s.) All five won their next games in the tournament — as Tennessee did against Mercer — and four went to the Final Four, including national finalist UCLA in 1980. No team before Tennessee was underseeded by even six spots; the Vols were slotted seven spots below where they should have been.
FiveThirtyEight’s model, which takes into account Pomeroy’s ratings and teams’ performance during the tournament, gives the Vols a 47 percent chance of beating Michigan on Friday. The game is essentially a tossup – a rarity for a matchup between a No. 2 seed and a No. 11.