Good reading. Last season Alabama gave up the 3rd most yards per game (352.2) of any national champion dating back to 1936. What qualifies as good defense has changed. Also the 2009 rule change regarding downfield pass-blocking that gave rise to the RPO was a big game-changer in favor of offenses.
The best defensive strategy now is stop the run, limit explosive plays, create turnovers, and run an offense that controls the clock. Opposing offenses that are patient will still do their damage in the short passing game, but you'll give yourself the best chance to outscore them.