Luck and self-delusion don't preclude the existence of each other. I may have said "this dog has 4 legs" but I certainly didn't say "everything with 4 legs is

Luck and self-delusion don't preclude the existence of each other. I may have said "this dog has 4 legs" but I certainly didn't say "everything with 4 legs is a dog". The climber who declares "I couldn't do it because there was bad weather" and doesn't persist: are they lucky to be alive to try again later? Or are they a deluded shirker expressing sour-grapes at someone else's success? These are not mutually exclusive. Equally, they could both be false. I don't deny determination and incremental (or paradigmatic) progress. Luck (or chance) is a factor that the successful (and their worshippers) seem only to eager to dismiss.