It wasn’t an all-decade team. But it was one of the all-time teams in ND football history. We’ve had three undefeated and untied regular seasons since Leahy left. 2012 was one of them. That's remarkable. Dissecting that season's results does not aid an anti-Kelly argument.
That being said, you raised an interesting question. Here’s the result of some afternoon research:
Since 1980, 27 teams have ended their year undefeated. This counts teams that either won their bowl games or were ineligible for a bowl. I only considered power conference teams or independents + BYU.
Four teams had at least six games decided by seven points or less:
- ’80 Georgia – Six including Tennessee, Clemson, Ole Miss, South Carolina, Florida and ND in the Sugar Bowl
- ’02 Ohio State – Seven including wins over Purdue (by 4) and Illinois (by 7)
- ’10 Auburn – Six including wins by three over Miss State and Kentucky
- ’12 Ohio State – Six including wins by seven over Purdue, three over IU and one over Sparty.
Four had at least four games decided by seven points or less:
- ’86 Penn State – Four close wins including Cincy, Maryland, ND and Miami.
- ’97 Michigan – Four including wins over ND, Iowa, Ohio State and Wazzu
- ’98 Tennessee – Four close wins + one by eight points
- ’84 BYU – Actually had five close wins over the Murderer’s Row of Pitt, Hawaii, Wyoming, Air Force and the Skunkbears in the Holiday Bowl for the “national title”
Eight had only three close games:
- ’87 Miami – All over top ten teams (FSU, OU, South Carolina)
- ’91 Miami – Over Penn State, Florida and BC
- ’92 Bama – Over Southern Miss, Tennessee and Florida
- ’93 Auburn (ineligible) – Over Ole Miss, Vandy and Florida
- ’94 Penn State – Over Michigan, Indiana and ILL-INI
- ’99 Florida State – Bowden’s only undefeated season
- ’00 Oklahoma – Over A&M, Okie State and K-State. Destroyed Texas and Nebraska that year.
- ’04 Southern Cal – Over Stanford, UCLA and Cal
Six had only two close games:
- ’81 Clemson – Wins over Nebraska in the bowl game and 10-8 over #8 North Carolina
- ’88 ND – Michigan and Miami
- ’97 Nebraska – Including the Mizzou Flea Kicker
- ’04 Auburn
- ’05 Texas – Season bookends over Ohio State and Southern Cal
- ’09 Bama – Close wins over Tennessee and Auburn (both unranked) in Saban’s only undefeated season
Four had one close game:
- ’91 Washington – A seven point win at Cal
- ’94 Nebraska – Over Warren Sapp and Ray Lewis in the Orange Bowl
- ’01 Miami – One speedbump against Va Tech and an 11 pt win over BC
- ’13 Florida State – Just one close one over Auburn in the title game
One team had zero close games:
- ’95 Nebraska – Their closest game was a 14-pt victory over Wazzu. The next closest were by 24 over #8 K-State and 25 over #7 Colorado. No one else came within 30 points.