What's most important for success in X?

On a very particular Q&A site, I saw the question "To what do you attribute your success?". A very broad question, intended for a very narrow audience, but any answer should apply generally. Many answers say something like 'tenacity' or 'embrace change' or 'have clear goals'. Which are all good. But here is my answer:

- good idea - addresses a real existing need in a way no one else ever thought of in just that way

- hard work - you can't just sit back and let people recognize your brilliant idea. Hard work can be either doing more (of the same stuff) or doing different (thinking harder)

- strategic details - getting the nuances just right can make the difference, that one tiny little thing, the subtle finishing touch whose lack

- good team - well prepared, good skill coverage, good connections

- luck - there are some many things that you don't know and can't know, historical accident, the whims of people, unexpectedly meeting an old friend

Any one of these can ruin things, but also any one can put you over the top into success. Sometimes you -can- sit back and let it run if you get real lucky (this is -very- rare, you're not -that- lucky). Often trying harder can compensate for bad luck.

The usual question is which single one is the most important, a good idea or a good team, or personality vs substance. The answer is always yes, but one can often compensate for the other.

Which one is the most important? The point of question like this is to determine which single one can you put your efforts into. Obviously you shouldn't neglect any but some are difficult to change like luck, but that's why you need to be well-prepared for when the opportunity arrives (or the disaster occurs).