What thread is safer for the arm, slider of splitter?

[slugger33]

Ha....well a MOD please change my title....I am a 15 year old kid trying to be a pitcher. Right now I throw a four seamer, two seamer, and a 3 fingered change up. My two seamer is by far my best pitch, it has a lot of sink, and sometimes even a slight curve. My change and four seamer are mediocre. I want to add something that has more movement. I can throw curves, but everybody my age throws them, it seems. I was thinking maybe a slider or a splitter. I have heard both could cause arm damage. Which one is safer to throw?

[Chris O'Leary]

Ha....well a MOD please change my title....I am a 15 year old kid trying to be a pitcher. Right now I throw a four seamer, two seamer, and a 3 fingered change up. My two seamer is by far my best pitch, it has a lot of sink, and sometimes even a slight curve. My change and four seamer are mediocre. I want to add something that has more movement. I can throw curves, but everybody my age throws them, it seems. I was thinking maybe a slider or a splitter. I have heard both could cause arm damage. Which one is safer to throw?

Splitter, but your hands have to be big enough to throw it well.