They are great at winning when it counts the most. The thing that hinders their going undefeated is that the play in the toughest conference in the country.
That doesn't really explain why the "National Champion" Gators were still able to play in the title game even though they lost to an unranked Ole Miss team. Texas' only loss last year was in the final seconds to a #5 Texas Tech team, but couldn't even go to the Big 12 championship game because there were so many highly ranked teams in the conference.
SEC, toughest indeed.