My dd will throw it once in a while during a game.Froze a few batters,but once they have seen it,not so much.She finds it fun to do when no batter has seen her do it ,throws it on 0-2 count first time,and then will mix it in here and there during the game,but used very little, and yes,we hear coaches asking if it is legal. Some weekends she will never throw it at all.My mother played fastpitch and modifed back in the mid to late 70s and on into the 80s. she was a slingshoter,so my mother loves when her granddaughter throws it,my mom is 68yo so it brings back memories for her.