On any given night, any two teams that play against each other in the big 12 can upset or lose a game. Many of the ten teams have been in the top 25 in the nation, some just missing. For example, Iowa State, a top ten preseason team, can lose to what now is a mediocre Northern Iowa team then turn around and beat a number one Oklahoma squad.
Teams such as Baylor, Oklahoma State, and Iowa State are what really makes this conference deep in my opinion, as Kansas and Oklahoma are the best two teams on paper, these three teams can win or lose to anyone in the conference. Many expected Kansas and Iowa State to be the top two, but with Baylor striving and beating many good teams on a five game win streak, they currently lead the Big 12.
What conference is next, honestly with the Iowa Hawkeyes starting 6-0 and beating Michigan State twice, it has dwindled the strength of the conference and stirred the pot of who will finally end up on top. ACC and SEC both having down years as Duke and Kentucky are both in the middle of their conferences with teams such as Clemson and Texas A&M being ahead of both.
The fact of the matter is the Big 12 is not only the deepest conference, it is also the best. With March Madness vastly approaching in the end the Big 12 will show out compared to other power 5 conferences.