I had a long response for that, but it's probably sufficient to say "It's not the SEC being head and shoulders above the rest, it's really just a small handful of teams in the SEC, and of those, only about two at a time at most."
I don't know that Vanderbilt is better than Northwestern, or Clanga is better than Illinois, for example.
Here's the thing about that: other conferences have either 0 or 1. So a "small handful" is a lot, actually.
It's not just Bama.
The top-end results show a depth that is unprecedented for any conference, ever.
Bama, Bama, Bama? Yes, but also 3 different NC programs in 3 years. 4 in 12 seasons. 5 in 14 season. 6 in 25 seasons. If those seem like unremarkable numbers, nope, they're UNPRECEDENTED.
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To match what the SEC has done in the past 3 seasons, guess how far back you have to go for other conferences?
B1G: 1965.....MSU's split NC 57 years ago
Want to include PSU, Nebraska, etc? It's still 1997. 25 years ago.
ACC: 1990.....GT's split NC 32 years ago
Want to include Miami, etc? It's still Miami in 2001. 21 years ago.
PAC: 1954.....UCLA's split NC 68 years ago
Want to include CU, etc? It's still CU in 1990. 32 years ago
B12: Technically 1939 or 1938....doesn't matter, the only teams to win anything between the Mississippi River and the Rocky Mtns are Texas, OU, and Nebraska. No depth, whatsoever.
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The SEC has had 6 different NCs more recently than any conference has had 3. The "Bama, Bama, Bama" narrative is lazy.