however john, if you see the perfect shot in your viewfinder, then you've already missed it.
t'was drilled into me, great action photography is all a guess. when someone asks "did you get the shot?" you say "i guess" because the truth is, you should have been seeing the momentary blackness which fills the viewfinder when a picture is taken.
at least that's how it was back when cameras had mirrors 'n stuff.