If you want to assign something to the narrative, you have to:
- Look at the history of bowl games perhaps over the last 25 years.
- Identify all bowl games over that span that fall into this category, where a team would be expected to have a letdown.
- Evaluate whether you've identified enough bowl games and set the selection criteria stringently enough to know whether your result is statistically significant.
- Evaluate based on the known relative strength of their team and the opponents what the expected results would be in these matchups (whether based on computer simulation, whether based on historical performance of schools of those relative strength, etc).
- Compare actual results to expected. Do they show a trend within statistically significant values?
If you get ALL that done, it still hasn't proven anything. It's suggested that within a certain confidence interval related to how statistically significant the result is, how likely it's a trend and how likely it's merely random chance. Because you can never really know.
Until then, we're all just talking out of our butts.
Well, let's see....going back 25 years,
the first end-of-season letdown was in 1996. Nebraska lost the BigXII CG to underdog Texas. UNL was in line to play #1 FSU in the Sugar Bowl, for a chance at a NC.
Nebraska beat underdog VT by 20 points, so no letdown.
Then in 1998, we had a bunch of fun. #2 UCLA pooped the bed @ unranked Miami in its last regular season game. It lost its bowl to Wisconsin in the Rose.
Next team up, Kansas State, lost the XII CG in an upset, then lost the Alamo to unranked Purdue. Those are 2 biggies in the letdown camp. UCLA and KSU started the year a combined 21-0 and ended 0-4.
Skip ahead to 2001....we have another pair of bed-poopers, including my Gators. Due to 9/11, big games were rescheduled to early Dec. #2 Florida, in line to face Miami for the NC, lost to Tennessee while both were top-5. Florida misses the SECCG and plays Maryland in the Orange. Florida wins by 33 - no letdown.
The following week, the Vols suffer an upset loss in the SECCG to LSU. No NCG shot. They play Michigan in the Citrus and win by 28, but was favored big. No letdown.
2003 is an odd case. #1 Oklahoma loses the XII CG big to #13 KSU...yet still makes it into the NCG. They lose to LSU, but they got into the game anyway, so it doesn't register here. Just wanted to explain it out.
2006 - The Game....#2 Michigan loses to #1 OSU. They don't get a rematch in the NCG, but play #8 USC in the Rose. The favored Wolverines lose by 14. Letdown.
2007 - Whoa Nellie.....#2 Kansas (WTF?) loses its last game to #3 Mizzou - no XII CG, no NCG...just a date with underdog VT in the Orange Bowl. The Jayhawks win, no letdown.
New #1 Missouri loses to #9 OU in the XII CG. They drop to the Cotton Bowl to underdog Arkansas and win by 31. No letdown.
Subsequent #2 West Virginia poops all over, in, and on the bed, losing to unranked Pitt in the last game of the regular season. Plays strong OU in the Fiesta, wins by 20. No letdown.
2008 - SECCG pits #1 Bama vs #2 Florida, with the Gators winning. Bama settles for the Sugar Bowl vs undefeated, underdog Utah and loses by 14 points. Letdown.
2009 - virtual repeat of 2008, SECCG pits #1 Florida vs #2 Bama, with the Tide rolling. Florida settles for the Sugar Bowl vs #4 undefeated, underdog Cincinnati. However, Florida drills them by 27. No letdown.
***this is a hard one to quantify for me, as Cinci was top5, but had a major talent disparity with UF.
2011 - #3 Arkansas has dream matchup @ #1 LSU in last game of season. Razorbacks get pasted - no SECCG, no NCG. Play #11 in Cotton, win by 13. No letdown.
2012 - Oregon and KSU nearly qualify for this, but lose a week too early and win their final, pre-bowl games, so meh.
2013 - 12-0 Ohio State rolls into the B10CG vs #10 MSU and loses, knocking them out of the NCG picture. The Buckeyes wind up in the Orange vs underdog Clemson. OSU loses by 5 in a letdown.
#1 Alabama faces #4 Auburn in the Iron Bowl and loses, so no SECCG or NCG. Bama winds up in the Sugar Bowl vs underdog OU and loses by 14. Letdown.
2014 - I'm going to include TCU here - who dropped out of the top 4 playoff teams after winning big in their last game. So they get sent to the Peach Bowl vs #9 Ole Miss and destroy them. No, they didn't lose on the cusp of something big, but they had the grand prize yanked out of their grasp and still had to go out and play an "other" bowl game. No letdown.
2015 - Iowa. #4, aligned to be in the playoff, they lose the B10CG to Sparty, which knocks them out. They have to play #5 Stanford in the Rose Bowl where they're spanked by 29 points. If it was a close loss between similarly ranked teams, that'd be fine. But getting rocked = letdown.
#4 ND loses their last game vs Stanford, eliminating them from the playoff. They go on to play #7 OSU in the Fiesta and lose by 16. Letdown.
2016 - Michigan. #3 UM loses @ #2 OSU in the Game. Winds up in the Orange Bowl vs #10 FSU, losing by 1 point. I don't know if this qualifies as a letdown, but I do know UM was the favorite.
2017 - Wisconsin is 5th, but teams above them will lose, so the B10 is a playoff play-in game for them. The Badgers lose, then must play #11 Miami in the Orange Bowl. They beat the Canes by 10. No letdown.
Auburn, with 2 losses is still in line for the playoff. But they lose to UGA in the SECCG and are out. They end up in the Peach vs undefeated, underdog UCF. The Tigers lose by 7. Letdown.
I may have missed one here or there, but there's plenty here. If we include TCU in 2014 and not 2016 Michigan, we end up with 19 instances of a team in line for a potential conference/national championship at the end of the regular season lost that chance and still had to get motivated for a bowl game.
Out of those 19, I've considered 9 letdowns, based on bowl opponent, margin of win/loss, and favorite/underdog. So while it's not a certainty, these teams were most often the favorite and only went 10-9, which is probably worse than one would expect. I'm confident that more-talented teams lose games they shouldn't when it's directly following the elimination of their highest goals late in the season.
This data shows that it's obviously not going to automatically happen all the time, but it is a thing. It would be less of a thing if these were 30 year olds and not 20 year olds. I do wonder if it would more or less of a thing if the bowls were played the very next week instead of a month down the road.