A 1/250th, it's not very hard at all, and definitely there's no luck involved at that sort of speed. In fact, it's pretty much like shooting ducks in a barrel. At 1/8th sec, the story is very different. I probably shoot 100-150 frames and expect to get one or two to use. I don't have the experience that the pros have - they do 15 race weekends in a year; I've probably only done 15 race weekends. I'm sure some of them are much more adept than I am at the slower shutter speeds.
_____ Brian... a bicoastal Nikonian and Team Member
My gallery is online. Comments and critique welcomed any time!