He definitely is not a trained sprinter as his form is, as you said, very choppy. When you look at him run from behind his legs and body are moving all over the place, not smooth and in perfect rhythm. Look at film of Carl Lewis and compare it to Bob Hayes. Lewis was smooth as silk, not a wasted movement, a perfect sprinter. Hayes was odd and choppy and his legs were out of rhythm and moving all over, much like Singleton. A football player running track. Both were blazing fast. The great thing is that Singleton will get even faster.