re: LSU 2015 national championship (what happened Les)

The 4 year cycle has been an evolving myth. Initially, it was hope to which we clung that recruiting classes following the 07 season would remediate the QB experience situation.

By 2010, the Tigers Defense was experienced and awesome again. The team had the overall talent to contend, BUT the offense was still not ready, yet. Very possibly a chain reaction result unplanned ( and not-successfully mitigated ) departure of Ryan Perrilloux. The 4 year cycle was born as the model to explain why such a talent rich team had title runs on 4 year intervals. It was simpler than accounting for the myriad events that carved history into its form.

By the summer of 2011 (if not sooner), people were explicitly talking about "the 4 year cycle". The interval plus repeatedly happening in the Dome added to it. The maturation of the offense allowed 2011 to happen in accordance with the hypothesis. In reality, roster chaos stunted the Tigers from 2008-2010, as Zebra interference may have kept LSU out in 06.

2012 and 2013 could have been title run years and that would've killed the myth back then. Circumstances didn't allow it.

To finally address your question; 2015 appeared to reinforce and validate the theory. LF7 was running over everything and the team appeared to be exactly what Les Miles always wanted. We know how it turned it out afterwards. In hind sight, the offense had been too traditional and unimaginative. It worked against great but not elite defenses, once the team hit that ceiling in 2015, it just collapsed upon them. Roster quirks and timing really helped foster the appearance of a greater phenomenon at work.