Nothing is more fundamental to helping you control and win games in Madden, or any other football game for that matter, than an effective running game. If you can run the ball, you can lower your risk of turnovers, wear down the opposing defense, control the game clock, convert third downs, open up your passing game, and most off all, frustrate the hell our of your opponent. Nothing is more demoralizing on defense than giving up a long, slow, 13-play touchdown drive, and running the ball can do that. Practice using spins, jukes, and straight arms, and you can often establish a high yards per carry average. Ultimately, a great running game is a great way to develop a deadly passing game.
Football is about match-ups and adjustments.
Part of what makes football so much more than just running and tackling is the strategic chess-match that defines big games. Big plays usually happen when a defender is in the wrong place or covering the wrong player. Audibles can be the key to helping work those match-ups in your favor. In Madden, you can set six offensive and defensive audibles that you can call at the line of scrimmage. On offense, you should set three runs and three passes, mostly from the same formations, so that your opponent won't know which audible you called, based on the formation.