George R.R. Martin discusses something he borrowed from Tolkien in writing A Game of Thrones, in terms of the initial structure of the book:
If you look at Lord of the Rings, everything begins in the Shire with Bilbo’s birthday party. You have a very small focus. You have a map of the Shire right in the beginning of the book – you think it’s the entire world. And then they get outside it. They cross the Shire, which seems epic in itself. And then the world keeps getting bigger and bigger and bigger. And then they add more and more characters, and then those characters split up. I essentially looked at the master there and adopted the same structure. Everything in A Game of Thrones begins in Winterfell. Everybody is together there and then you meet more people and, ultimately, they’re split apart and they go in different directions. But the one departure from that, right from the first, was Daenerys, who was always separate. It’s almost as if Tolkien, in addition to having Bilbo, had thrown in an occasional Faramir chapter, right from the beginning of the book.
Tolkien, who was notoriously dilatory, managed to finish The Lord of the Rings. However, it appears that Martin lost control of the GOT and has abandoned it and its characters halfway through. Now, he’s too old to complete it. Perhaps his publisher will find a coauthor to do it. Soon, preferably while Martin can still have some input.