When I started writing Macedonia (my latest fiction), I had only one rule. It had to have 59 chapters. This is because the book is a re-vision of Macedonio Fernandez's 'Museo de la Novela de la Eterna', which began with 59 prologues.
In the final prologue, Macedonio wrote: "I leave an open book; perhaps it will be the first "open book" in literary history, that is, the author, wishing it were better, or at least good, and convinced that its mutilated structure is a dreadful discourtesy to the reader, but also convinced that the book is rich in suggestions, hereby authorizes any future writer whose temperament and circumstances favor intense labor to correct and edit it freely, with or without mentioning my name. The task will not be small. Delete, amend, change, but if possible, let something remain".
As of today I am 49 chapters into it. The end is coming soon (repent!). As I go along, I find I am discovering new elements of the so-called plot every day, and have to go back and revise. This is how it should be. When I stop discovering what the novel is about, it will definitely be the end