We are in an era of football dynasties.

The Patriots are still looking to become the first or second NFL dynasty to win five Super Bowls, depending on whether we think of the 49ers' transition from Bill Walsh and Joe Montana to George Seifert and Steve Young as marking the end of that '80s dynasty. In the other football, Barcelona are going for a fifth Champions League title since 2006, which would put the Blaugrana in the realm of the best club team of all time.

And in our little corner, Alabama just won its fourth national title in the last seven years.

So how does this Alabama epoch stack up against other college football dynasties?

Specifically, how does it compare to other teams since 1936 that have won at least three national titles in a seven-year stretch?

Why start in 1936? Because that was the first year of the AP Poll. College football was becoming a national sport and saw the birth of a measure that is still used. A handful of teams did have championship runs before the AP Poll.

Why three national titles in seven years or fewer? This standard covers nearly two full recruiting classes, which requires sustained excellence while not being over-inclusive. To avoid just using Alabama's run of four titles in seven years as the measuring stick, I've cut the number of required titles from four to three. Also included is a separate list of schools that won three or more titles in eight years.

Finally, we are going to limit ourselves to teams that won titles from one of the two major polls (AP and UPI/Coaches), because otherwise, this exclusive club would no longer be exclusive. If we use every current selector, let alone every past selector, this will go off the rails. I'm sure Edward Litkenhous was careful with his rankings, but we'll have to make do without his input.

How many dynasties do we have, based on these standards?

	Titles	Average SRS	Median SRS	Winning %	Average schedule strength
Alabama 2009-15	4	22.15	23.69	.893	5.65
Nebraska 1993-97	3	22.47	22.22	.953	4.12
Miami 1985-91	3	21.94	22.73	.916	5.1
Miami 1983-89	3	19.57	20.29	.871	5.02
Alabama 1973-79	3	23.33	23.05	.904	7.5
USC 1972-78	3	21.12	20.9	.835	8.94
Alabama 1961-66	3	22.51	23.11	.916	6.84
Oklahoma 1950-56	3	20.65	20.92	.917	3.65
Notre Dame 1943-49	4**	27.96**	28.31**	.906	11.06**

If we just extended our time period by a year, then we would pick up three additional dynasties.

	Titles	Average SRS	Median SRS	Winning %	Average schedule strength
USC 1967-74	3	20.75	19.98	.822	9.45
Texas 1963-70	3	19.40	21.04	.814	7.30
Ohio State 1954-61	3	18.33	18.32	.779	9.40

The SRS team quality metric and strength of schedule numbers come from the invaluable College Football Reference. For both, the higher the number, the better.

Note: Bobby Bowden's Florida State and Pete Carroll's USC come up just short here. With better kickers and one stop in Pasadena against Vince Young, they'd both be in. (The AP voted USC No. 1 in 2003, despite LSU beating Oklahoma in the BCS Championship.)

With one major exception, Saban's Alabama stacks up well on paper against anybody.

Alabama against Notre Dame**

Notre Dame from the '40s is in a different stratosphere: four national titles in seven years, the highest mean and median SRS ratings, a winning percentage north of 90, and a crazy strength of schedule number. Frank Leahy's teams played and beat the best.

That said, the Notre Dame dynasty existed under unique circumstances. Leaving aside basic differences between football then and now, the first half of the run took place when most young American males were occupied by World War II. Notre Dame was not among the 54 programs that missed at least one season during the war.

For instance, when Notre Dame won the national title in 1943, the remainder of the top 10 included noted powers Iowa Pre-Flight (a Bill Connelly favorite), Great Lakes Navy, Del Monte Pre-Flight and March Field.

(This is also when Navy saved Notre Dame as an institution, a favor the Irish repay by continuing to play the Midshipmen every year. So the team that produced what might be college football's best seven-year stretch was playing at one of many schools hurt by the redirection of resources to fight Nazi Germany and Imperial Japan.)

The ancient bowl system also leaves unanswered questions. The 1946 Irish won the national title ahead of Army, which the Irish tied 0-0 at Yankee Stadium in one of the most famous games in football history. The 1947 team won the national title ahead of a Michigan team that also went unbeaten and crushed USC so thoroughly in the Rose Bowl that the AP conducted a special post-bowl poll, won by Michigan.

The system was so limited that the Irish were not permitted to answer questions in the same way that Saban's Alabama can. The same is true when comparing the modern Tide -- the only team on the list from the BCS/Playoff era -- to most teams in history, but the further back we go, the harder the task becomes.

Alabama against Nebraska and Miami

Before Alabama, there was Tom Osborne's Nebraska.

The average Husker team from the mid-'90s dynasty was essentially equal to Saban's average team. Nebraska had a better winning percentage against an inferior schedule.

The big difference is that Nebraska's dynasty was only five years (the Huskers lost three games the year before the dynasty and four the year after), whereas Bama's is seven and counting. If we pushed Nebraska out to a seven-year window (1993-99), then the Huskers would drop down to a .911 winning percentage, which is only slightly higher than the .893 Bama earned against a tougher schedule. Nebraska's average SRS rating would be 21.44, about a half-point lower than Bama's.

The great what-if is what would have happened had future Congressman Tom Osborne not retired at the age of 60. (Saban is 64. Count your blessings, Bama fans, that Nick does not appear to be interested in politics.)

Like Nebraska, Alabama is close to Miami's overlapping seven-year runs in the '80s and early '90s. The unique aspect of Miami's dynasty is that the Canes won national titles under three different coaches during their nine-year run.

Alabama against Ohio State and Oklahoma

By median, mean, and winning percentage, Saban's Alabama is well ahead of Woody Hayes' dynasty from the '50s.

That said, Hayes continued to produce excellent teams through the '60s and '70s. Ohio State fans generally maintain that the '68 team was Hayes' best, although SRS gives the nod to the '73 team. (You want an argument in favor of expanding the Playoff? Try to pick four teams in 1973, especially if Oklahoma were not on probation.) Thus, Saban's Alabama is ahead of the apex of Hayes' Ohio State, but it's hard to imagine any modern coach having Woody's longevity.

Oklahoma's dynasty under Bud Wilkinson produced the record 47-game winning streak. However, the Sooners played the weakest average opponent of any of these dynasties, despite playing in an era of fewer obvious body bag games than now. Saban's Tide have played tougher schedules, they have one more national title, and their ratings are higher.

Nick Saban against Bear Bryant

College football had three dynasties in the '60s and early '70s: Alabama, Texas and USC. By SRS, the current Alabama dynasty is better than the latter two. Saban's Alabama has one more national title than each. Alabama's winning percentage in its current run is also significantly higher, although it should be pointed out that USC and Texas played stronger schedules.

So that just leaves Saban against the Bear's two streaks. In the first half of the '60s, Alabama won three national titles and added an unbeaten team in 1966. Because of the '66 polls, Saban's dynasty has one more national title, but the Bear's Alabama had a slightly better winning percentage against a slightly better schedule.

* (This is made up for by the 1973 UPI Poll awarding Bama the title over a Notre Dame team to which it would lose in the Sugar Bowl.)

The SRS numbers are quite close. If there is a close fit for Saban's Alabama among modern college football's eight other seven-year dynasties, it's Bryant's Alabama.

The Bear followed his apex with a fallow period, losing 15 games in four seasons from 1967-70. It was partly the adoption of the wishbone before 1971 (cribbed from Texas, whose dynasty was coming to an end) that led to the Tide's resurgence. And even the offensive conversion did not lead to postseason success, as Bryant went winless in eight straight bowl games before beating Penn State in the '75 Sugar Bowl.

None of these other 12 dynasties won more than four national titles in a decade. A fifth for the Tide would put them past all comparators.

And Alabama, fresh off its sixth straight No. 1 recruiting class, is the 2016 season's favorite, according to the oddsmakers and the advanced stats.

Thus, from a historical perspective, the immediate future poses two interesting questions:

1. Can Saban's Alabama become the greatest dynasty in the modern history of the sport?
   
   
2. Is Urban Meyer -- with three national titles at two schools and two additional unbeaten seasons in a 12-year stretch -- creating a competing dynasty in Columbus? Ohio State's SRS ratings in the last two years have been above 20, i.e., dynasty levels. We could be on the cusp of that rarest of college football phenomena: competing dynasties.