Offense
You must have a balanced attack proving that you can both run the ball and pass the ball. The most important part of that balanced attack is being physical at the line of scrimmage when running the ball. The offensive line needs to dominate at the point of attack. Once you establish the run, it opens up the passing game. If you can dominate the line of scrimmage on offense, impose your will and take the life out of them physically, you’ll have much success.
Defense
The #1 priority of the defense is to be able to stop the run. It’s paramount to having a good defense because if you can stop the offense from running down your throats it means that you’re controlling the line of scrimmage. Again, physicality. Imposing your will on the opposing teams offense. It turns a team into a 1 dimensional team. Then you have them where you want them. If you can’t stop the run, you’re doomed in the playoffs.
Bottom Line
It’s all about physicality. It’s impossible to do either of the above if you can’t control the line of scrimmage. And you can’t just do 1 well, you have to do both well. Physicality is what football is all about. Controlling the line of scrimmage. The Cowboys haven’t been able to do both in the same season since the early 90’s. Yet CZ fans want to blame just one person for all the playoff failures. To put it nicely, how naive.