Contrast between opening/closing scenes
This is one of my favorite movies (I actually saw this one in the theater when it came out in Summer 1988).
I've always loved the contrast between the opening scenes (when Susan Sarandon is making her way to the ballpark on a fine Spring evening) and the ending scenes (where it's just a depressing, dreary, steady rain...I believe the game was eventually rained out). I love how that mirrors a baseball season so much...start in the Spring, when the expectations, hopes, and optimism are high; and finish in the Fall, when those expectations are over and your season "is what it is" by that point. I just love the way this contrast is shown in the movie.