Inspired by @wxmoose himself looking into this and asking me about it, I decided to take a closer look at the supposed Duke hangover that happens after a team beats Duke and find out if its a real or just something closer to an anomaly that's caught on over time.
Let's lay out our criteria first
- We'll compare teams using KenPom ranking since there's a nice historical backlog there that ranks every team as opposed to the top 25. We'll use final season rankings as well, because Pomeroy only recently started keeping track of rankings from game to game.
- We'll only focus on conference games, starting in 2008 (so right after their 8-8 season) and removing the regular season finales against UNC (since their next game would be in the tournament and not the regular season). The idea here is to see whether there's a hangover in season from playing Duke, not whether Carolina specifically sucks in the ACC tournament after beating Duke (they do not, for the record).
- Home court matters a lot in college basketball. For a game to be a toss-up, the road team needs to be about 20 spots higher in the rankings. For the road team to be a strong (70%+) favorite, it needs to be closer to 50 spots higher.
2008
#69 Wake beat #10 Duke at home, lost to #3 UNC by 16 points on the road
Hangover Effect: Nope, they were huge underdogs to UNC and lost by about what you'd expect
#39 Miami beat #10 Duke at home, beat #64 Maryland at home by 15
Hangover Effect: Nope, took care of business at home
2009
#27 Wake beat #12 Duke at home, lost to #99 GT by 2 on the road
Hangover Effect: Yep, even on the road that's a game they would have been a 7-8 point favorite in
#25 Clemson beat #12 Duke at home, lost to #31 FSU by 4 at home
Hangover Effect: Yep, lost as a 70%ish favorite in their next game
#1 UNC beat #12 Duke on the road, beat #50 Miami by 4 on the road
Hangover Effect: No - underplayed to expectations slightly but won
#70 Boston College beat #12 Duke at home, lost to #50 Miami by 11 on the road
Hangover Effect: No, would have been decent underdogs at Miami and lost. Again they maybe underplayed expectations by 3-4 points.
2010
#28 Georgia Tech beat #1 Duke at home, lost to #80 Virginia by 7 on the road
Hangover Effect: Yes, underplayed their expectations by about 14 points
#70 NC State beat #1 Duke at home, lost to #13 Maryland by 24 on the road
Hangover Effect: Maybe, but I'd lean toward no because they were 12-13 point dogs anyway
#13 Maryland beat #1 Duke at home, beat #80 UVA by 8 on the road
Hangover Effect: No
2011
#29 FSU beat #4 Duke at home, beat #97 NC State by 13 at home
Hangover Effect: No
#45 VT beat #4 Duke at home, lost to #67 BC by 15 at home
Hangover Effect: Yes, by a good bit as VT would have been 7-8 point favorites and got thumped
2012
#25 FSU beat #21 Duke on the road, beat #217 Wake by 23 on the road
Hangover Effect: No, Bzdelik'd
#50 Miami beat #21 Duke on the road, beat #98 VT by 16 at home
Hangover Effect: No
2013
#34 NC State beat #6 Duke at home, lost to #48 Maryland by 1 on the road
Hangover Effect: No, Maryland was the favorite and won
#14 Miami beat #6 Duke at home, beat #121 FSU by 24 at home
Hangover Effect: No
#48 Maryland beat #6 Duke at home, lost to #96 BC by 11 on the road
Hangover Effect: Yep, Maryland under-performed by about 15 points
#40 Virginia beat #6 Duke at home, lost to #97 BC by 1 on the road
Hangover Effect: Yep, UVA under-performed by around 7 points
2014
#67 Notre Dame beat #16 Duke at home, lost to #75 NC State by 7 at home
Hangover Effect: Yes, ND under-performed by about 14 points
Final Verdict
7 hangovers
11 non-hangovers
So, about 40% of the time teams play worse than expected after beating Duke during the regular season. Which, assuming teams over-perform/under-perform/meet expectations at an equal clip, is only about a 7% difference from what you'd expect out of any team in any game.
Sorry Duke hangover, but I'm afraid you don't really exist.
