No doubt, going undefeated in college football is a rare and difficult feat. Over the past quarter-century, three local teams have achieved perfection.

BYU did it in 1984 and Utah has done it twice in the past five years, including the recently completed 2008 season, capped by a dominating 31-17 victory over Alabama in the Sugar Bowl.

Which of those three teams was best? It's fun to debate, but, truth is, it's hard enough to compare teams year-to-year, let alone era-to-era.

"The games are different now," said former BYU coach LaVell Edwards, who guided the Cougars to the 1984 national championship. "Any team that goes through an undefeated season has to have some breaks. We had ours and (the 2008 Utes) had theirs. But it's a different time and what all three teams did were great accomplishments."

While there have been debates about which Utah team was better — '04 or '08 — many argue that BYU's 1984 team isn't even the best in school history, citing the merits of the 1980, 1983 or 1996 squads.

Still, those teams didn't go unbeaten.

"The more I'm around football, the more I realized how difficult it is to go undefeated," Robbie Bosco, who quarterbacked the Cougars in '84, said this past week. "I don't care what league you're in or who you play. The main thing was, we had three or four games we could have lost. But guys made plays when we had to. Sometimes, a little luck is involved."

How difficult is it to go undefeated?

"There's only one school in the country that did (this season)," said Utah athletic director Chris Hill, "which tells you how hard it is."

Maybe the most relevant debate is this: Which of those three unbeaten teams had the biggest national impact?

The 2004 and 2008 Utes, and the 1984 Cougars, are linked not only by their undefeated seasons, but how they each helped alter the college football landscape.

BYU's one and only unbeaten season in school history produced an improbable, and controversial, national championship that helped usher in the current Bowl Championship Series system. Because of that BCS system, the Utes were denied a shot at a national title both in 2004 and 2008. Then again, maybe without the BCS, they wouldn't have had the opportunity to play in the prestigious Sugar Bowl.

Utah's 13-0 season attracted widespread national attention and has been a vehicle promoting change in the BCS system. Several national columnists declared the Utes national champions this week. Utah finished No. 2 in the Associated Press poll, garnering 16 first-place votes, behind No. 1 Florida.