Your screwball moves? Then you are the only one that can do it. I need to see it. I was behind Jenny Finch when she was throwing hers and hers did not move other than be on an angle. Some pitches may ride inside to the batter with a little flick of the fingers but a true screwball (opposite of the curve) I have yet to see.
Who was the girl from UCLA a few years back? She threw probably 80%+ screwball and her ball definitley did move.
Though I agree with you at least at the lower level most of the girls I see throwing a "screwball" it is more of an inside fastball with different rotation. I think most grils who throw it tend to get too much of a reverse bullet spin on the pitch rather than the true 9-3 rotation (do I have my clock directions right?) for a true screwball.