I was having a catch yesterday and I was trying new grips to get movement and than I remember the beginners curveball grip from this website (I don't know where). But I forgot how to throw it so I just threw it like a fastball and let it roll off my index finger a it slid. It did exactly what a slider does. Do you think this would be a good secondary pitch, maybe a show me pitch? And is it any good for the arm or could it be harmful? I don't think it would hurt because I'm just throwing it like a fastball. Any opinions/suggestions? Thanks.