Winning attitude/culture.
Talented, high football IQ players, that are committed to winning.
Know who you are and what your identity is.
mental toughness and handling pressure.
Most of what everyone wrote can be tied to one thing: Coaching.
A good coach:
* Creates a winning attitude and culture
* Demands discipline from his players
* Develops successful plans
* Motivates his players
* Creates a team identity
* Demands mental toughness
* Demands consistency in the performance of his players
So, coaching has a ton to do with success IMO. But, IMO, there is a caveat:
There has to be an effective front office that acquires/drafts talented, intelligent, motivated, disciplined players.
If the FO does that, the coaches have a real good chance of success.
If they don't? I don't care who the coaches are, they'll struggle. There have been plenty of examples of coaches that did very well with one team, moved on and faltered.
Why? Because in most cases, the foundation wasn't there that second go 'round.
With ths possible exception of Bellichick (can't stand the guy but have to respect what he gets out of a team no matter the circumstances), coaching will only take you so far.
Get a FO who works in harmony with the coaching staff on the types of players they want... and what the scheme will be and you have success most times.
I think Snead and Fisher value certain attributes in players that may not be successful. So, while they are in harmony, the song is still out of key.
They really rely on physical talent... don't seem too concerned about intelligence, discipline, attitude, etc.