I put genetics way down on my list of things that are important for generating speed. When I mentioned "strong core, arm, and flexibility" I was talking about conditioning to achive these factors not something you are born with. Whether or not someone is a "gifted athlete" or genetically superior is almost irrelevant to this post. Our DD's bodies are what they are, I am interested in how do we take what they have been given and optimize their performance. You acheive that with proper mechanics, lots of practice, trial and error, conditioning, great attitude to want to get better, and continuing to perfect your craft. When I mentioned "longer arm circle" I mean, all things being equal, longer arms can help with speed, but there are too many other factors that contribute to ball speed to chalk it up to genetics. 100% agree with ifubuildit's post.
Apparently,you didn't read my last post. I agree that you can better yourself with conditioning and improve your chances of being a good pitcher, but the superior athlete doing the same conditioning and the aforementioned will outperform those not so gifted athletes.As far as something being irrelevant to this post, who was it who brought up the movement, change of speeds etc. The one who posted this thread asked about creating speed. Touche'