As always all great movies are based upon novels and this movie is no exception, This is a unique and slightly disturbing movie. The film has it's advantages compared with the original story which I think was amazing in it self and with it's deep meanings which you have to look deep within the meanings of the symbols to find the true meanings. This film is a pinnacle of world cinema and is everything that a real masterpiece has to have and add to that superb diction, a great screenplay, casting plot and a theme that deals with one timeless concept and that makes for a timeless classic. This film makes us focus on the humanistic categories, without which a man is not, mean while admitting truth that no ones perfect and that the less important short coming of a mans life and a wish is acceptable in our not so idealized life. The film has advantages compared with the original story, if you eliminate with the original narrative sly and the film becomes more objective and realistic perception and by stowing Ratched as an almost nice person and winding the scope of her character made the McMurphy-Ratched conflict more powerful and substantial.
Chief Bromden's narrative is excellent in this film with Jack Nicholson as the prefect person for McMurphy, the movie also flourishes with brilliant dialogue that is witty and amusing capturing the true effect of the film. And to me there is not one scene in the film in which I thought was boring or out of place.
In the end in my opinion the film is very good. This is film is a terrific dream that's about more then just a story about a mental institution or a story about human nature and reaction, this movie is about how we chooses to live.