Some teams have studs at quarterback. Most don't. We don't need top-notch passers to win Madden games. Any player can be a force by mastering the fundamentals. Mix surrounding personnel, the strengths of your quarterback, and a little practice make any quarterback on the game a potential winner. WFColonel56 gives us another tip to win with bad quarterbacks.
Maximize the Talents of Other Players
The quarterback is the most influential player on the field because his skill set dictates how opponents plan for a game, but our quarterback's performance determines how defenses play the game. Lesser skilled quarterbacks shouldn't be throwing nearly as often as passers that throw well.
Use receivers that can catch. If we have a receiver with a knack for catching jump balls, take a high shot where he has a height advantage. If our receivers are quick, throw low passes that can be caught for possession right out of a cut.
If your defense is stout, run the ball and to work the clock to put opponents in predictable situations. Think about how to execute every play but focus more on how each play affects the next.