Yes, it is very critical you do this.
Set yours AND your opponents agression, sub and run/pass ratios to default for BOTH OFFENSE and DEFENSE. Then change your opponents, not your own, offensive run/pass ratio to what jukeman suggests. You don't need to change your's because you are calling the plays and it will have no effect.
After the game change ALL of the sliders for both yours and your opponents OFFENSE AND DEFENSE back to sm27's updated settings.
I made the mistake for my first two non-conference games of not setting the agression and sub sliders for both teams back to their default and in essence you are left with your opponent subbing alot and your team subbing hardly any at all. Both games were way too easy and I took a guess at the fact that something was wrong. That was the problem.