re: Why can't Auburn maintain success.

S&P 2015 Top Defenses (efficiency, which doesn't rely on just yards so it makes it more fair to teams running tons of offensive plays)

1. Alabama - pro style offense
2. Michigan - pro style offense
3. Boston College - pro style offense
4. Clemson - spread up tempo offense
5. Northwestern - spread offense, medium tempo
6. Florida - pro style offense
7. Wisconsin - pro style offense
8. Ohio State - spread offense, not so much up tempo in 2015
9. Washington - pro style offense
10. Florida State - pro style offense
11. Georgia - pro style offense
12. Michigan State - pro style offense