If photography has a lot of luck involved than luck must favor the prepared. Knowing what you need to make an image before that image even comes to fruition is a photojournalist's job.
It is similar to that of a fortune teller, you have to know what is going to happen before it even happens so you are ready to make the frame. The only difference is photographers don't have an extrasensory ability, well I don't at least.
That is where intuition comes into play. Anticipating the action, and being ready to capture it. When I was the photo editor at my college's newspaper I would often tell new photographers that if you see the frame you want you probably just missed it.
You cannot just see the moment you have to predict it, analysis the composition, prepare your settings, make sure everything is in focus and fire. A lot to do in the matter of a split second but there are things you can do to compensate. Don't get me wrong photographers aren't the fastest acting people ever, they are just the next best.
Some of the best photographer's minds work about as fast as Usian Bolt can run (I can only hope to be half that fast one day).
When the world's first psychic photographer starts shooting I can kiss my job goodbye.
Until next time, take care!