Baseball is a nineteenth-century pastoral game. Football is a twentieth-century technological struggle. Baseball is played on a diamond, in a park. Football is played on a gridiron, in a stadium, sometimes called Soldier Field or War Memorial Stadium. Baseball begins in the spring, the season of new life.
Football begins in the fall, when everything's dying.
In football you wear a helmet. In baseball you wear a cap. In football you receive a penalty. In baseball you make an error. In football the specialist comes in to kick.