Steve Sarkisian, Larry Scott and Marcus Mariota are three reasons for the Pac-12's momentum. AP Photo

When I wrote in an Insider article two years ago that the Pac-12 had an opportunity to close the gap between it and the SEC as the top college football conference in the country (an article that drew its fair share of discussion), Pac-12 commissioner Larry Scott was still in the formative and visionary process of building up the league. He had brokered the richest television deal in college sports, and the conference was taking shape with its new members and new direction.

Two years later, the conference continues to close the gap, and while its 12 members cannibalized their own chances at a BCS title in 2013, the vision continues to look very promising. Here are four reasons the Pac-12 continues to pose a long-term threat to the SEC in terms of college football supremacy.