I never played competitive ball, but I played pickup ball with my friends all the time when I was younger. I threw a 4-seamer, splitter, straight change, and a disgusting curveball that dropped like a foot at the plate. I also threw in an occasional knuckler, but you could tell it was coming because I changed my arm action for it - I threw everything else from a 3/4 angle, almost like Kevin Brown (whom I idolized when he was a Padre in '98 - hence the splitter), but the knuckler was over the top. It danced, though.
I tried out for the baseball team at my HS my freshman year, and I threw well when I was practicing. But as soon as I got in front of a coach, I freaked out and got all wild. I didn't make the team. :(