I watched Oprah Winfrey's Super Soul Sunday this past Sunday. She had an author on, Steven Pressfield (author of
The War of Art). He talked a lot about resistance (what economists would call barriers to entry), as it pertained to his breaking into book writing.
He said something interesting.... There is a way to get to the gold (getting an agent, getting published, becoming successful, and so forth). He had to figure out how to get passed the dragon protecting the gold. Finally, he did it.
Most important, to me, are two (and they carry equal weight): 1) Skill; and 2) Properly-guided determination (consisting of four elements).
I think luck becomes more important with reduction of design of commercial appeal for a novel. Think of things with high commercial appeal; they were designed to succeed. Lee Kerslake (Ozzy's drummer on the Blizzard of Ozz album) said in an interview that there was no way the album would not succeed; it was too clever. Guns n' Roses Appetite for Destruction was designed to succeed, and it did.
Twilight and The Hunger Games, at least appear to, mimic Harry Potter's book layout (evidence
one,
two). These books were designed to succeed, and they did. Granted, Twilight was rejected by 14 agents before the author found one. I do not know specifics, but I assume some of the rejects might have been automated, non-compliance of agent interests or submission guidelines, or something similar.
Music and novels are not the only venues offering designed-to-succeed products. Car manufacturers, gadgets, and what not; it's everywhere.
If a book is not designed to be maximally, commercially successful, luck is important for sure. I think luck is replaced by greed (of author, agent, and publisher) the more commercial-appeal potential an author can bring at the beginning. This includes a high degree of skill (technical and commercialization), but I think an agent (and/or publisher) might be more willing to work with a new author if the product may bring greater profits (as long as submission guidelines are met, some level of skill is demonstrated, and so on). This is not to suggest all agents and publishers work this way.
Is luck ever 100% not present? No! But luck is diminished by other elements.