Does the author see the whole story or make it up as he goes along?

Thanks to extremely demanding week at work this blog should be called Elliot's Not Reading, but did read last night a few more pages of Roberto Bolano's "Monsieur Pain," and continue to find it strange and impenetrable and therefore typically Bolano and very readable but who knows if the payoff will be there in the end? Some of his better works, in homage to other great Latin American writers, are labyrinthine and mysterious, but the weaker ones (they are few) seem more improvisational. In a great mysterious story or novel you must have the sense that the author has seen it whole and is in complete control throughout, that you're in the hands of a good pilot who will bring you in safely. In a weaker novel (same holds true for movies) you sense that the author doesn't really know where he/she is heading, the author is feeling his/her way along the route, and you might be taking a long journey to nowhere. Bolano is occasionally the victim of this - a prolific, imaginative author who seems sometimes to be literally writing for his life, he was not the type, I imagine, to abandon anything he started. He was one of the rare breeds of professional writers, living "by the pen" alone. The mystery deepens in M. Pain as we learn that the title character, an acupunturist, is now being paid, or actually bribed, to not treat a patient, the Peruvian poet Cesar Vallejo. Totally unclear (to him and us) why the two Spanish strangers would pay him to let Vallejo alone to die. More will unfold, no doubt, but will we get answers or just more puzzles?