I pitched slingshot in the military traveling leaque is korea in 1986 . I was 7 and 0 . strike out per was 7 . I could only throw the dropball . I am windmillI also come from the 70's era and pitched slingshot and I can tell you from experience that one is not better than the other. There are slingshot pitchers that could hold their own with any windmill pitcher of today. Today it is looked down upon because it is not used by the big name players in the game and that is OK until a young lady throwing the slingshot is not taken seriously because she is different. I had one of my students that took to the slingshot over the windmill and her school coaches would not even look at her in tryouts because she was pitching "illegally". They lost out due to their ignorance but, unfortunately, this is not uncommon.
As for mixing the styles, windmill using the slingshot as another pitch is an awesome combination I teach to any student that can make the transition for a strike but it is another pitch that should be used only on occassion. If done properly and used sparingly it is a very effective tool. The slingshot pitcher mixing in a windmill is not only less effective because the batter has time to see what is happening but it is also more apt to cause an injury unless the pitcher has worked both styles consistently through her training.
pitcher . if I could have thrown a good riseball I would had kept pitching
slingshot . throwing windmill I have a very good rise , drop , and nasty
knuckle ball when I change speeds it float .
where in NC are you at . I played majorand class A from 1975-1977 when I was station at Fort Bragg .