Earlier quoted context omitted.
Luck favours the prepared.
Luck by definition is an independent variable. Edit: I don't know who downvoted me, but this is the definition of luck according to Google: "success or failure apparently brought by chance rather than through one's own actions"
It’s like playing blackjack. Ultimately, it all comes down to luck, but you are significantly increasing your chances of winning by employing certain (legitimate) strategies rather than playing your hand randomly and hoping for luck to hit you.