It's probably the biggest factor that's never talked about. Seattle this year. San Francisco last year. Dallas a few years back. Teams that go an entire season with freakish luck on the injury front usually go on to do big things.
They also crash harder the next year.
Well heck, even San Fran this year. Counting the Justin Smith and Alex Smith injuries they've had starters miss just 6 games this year. That's just astounding. Is it just incredible luck for them and bad luck for us, or are they doing something we could emulate? I know the common cliche is every team is banged up at this point, but realistically Seattle and San Fran have had almost 0 major injuries the entire year.