James H. Smart helped start the Big Ten, possibly because he was tired of Purdue being called a mid-major.

Yesterday at Insider I ranked my top five mid-majors, and in response I heard back from some readers who felt that the hardiest of hoops perennials — what’s a mid-major? — perhaps merits rehashing in this era of wanton realignment. Fair enough. What’s a mid-major?

A mid-major is a team from any conference except the ACC, American, Big 12, Big East, Big Ten, Pac-12, or SEC. 

Traditionally a “major” conference was one that sent teams to BCS bowls in football. That definition broke down, of course, with the implosion of the old Syracuse-equipped Big East. So now I guess we’ll have to go by basketball performance to hash this out, and one of the first things I noticed this season was that the seven conferences named above had achieved a neat degree of separation from the rest of Division I on KenPom:

1.  Big Ten   .8318
2.  ACC       .8050
3.  Big East  .7913
4.  Big 12    .7890
5.  Pac-12    .7659
6.  American  .7502
7.  SEC       .7422
8.  A-10      .6896
9.  WCC       .6590
10. MWC       .6217

That’s suggestive, but if we went by KenPom ratings alone the Pac-12 would have been banished from the major-conference table on a couple of occasions in recent years. Besides, the Atlantic 10 did send five teams to the NCAA tournament last spring, and that sounds awfully un-mid-major-like.

If the A-10 had held on to Butler, Temple, and Xavier, this discussion could proceed along different lines. But the fact that the A-10 lost those members to two conferences brought into being by an ACC talent raid is still another indication of the league’s place in this particular pecking order. And now that the Bulldogs, Owls, and Musketeers have moved on up, so to speak, this major/mid-major thing actually sorts out rather tidily.

The seven major conferences have accounted for the lion’s share of recent NCAA tournament wins. In fact it’s not too much to say there’s a sheer cliff between those seven and the rest of Division I.

NCAA tournament wins since 2000
Based on 2013-14 memberships

1.  ACC        165
2.  Big Ten    130
3.  SEC        111
4.  Big 12     106
5.  Pac-12      87
6.  American    80
7.  Big East    75
8.  A-10        26
9.  WCC         23
10. MVC         16

Naturally the major conferences have won all those games by getting way more bids to start with (and by securing higher seeds), but that’s kind of my point. This isn’t simply a measure of tournament performance, it’s also a window into how the NCAA’s men’s basketball committee views Division I every March. Speaking in terms of current members, the big seven conferences have produced the last 23 national champions, and 46 of the last 47.

I do think the boundaries between majors and mid-majors are more fluid now than at any time in recent memory, and certainly any definition that embraces the likes of UCF and TCU while excluding Gonzaga and VCU is not the last word in utility. Maybe we need a better and specifically a more granular way of sorting out teams than a simple yes-no dichotomy. I’m all ears.

But if we’re going to keep doing what we’ve been doing and label conferences according to “major” and “mid-major” branding, the dividing line in 2013-14 is too plain for haggling. There are seven major conferences.