Listen, it could have worked.

Rating: 1/10 (4 January 2012)

So, I think it's well established that this film is a failure of the "is it real?"" plot. People here are quick to cite the fact that this genre's recent popularity may have jaded them and made them aware of what was going to happen.
But the problem is not the formula, the problem is the execution. Many reviewers have mentioned "Fight Club" and "Memento" or "Beautiful Mind" as examples of successes in this storyline. But the crucial difference between these films and The Machinist is that, in the more successful films, the events which are later to be explained as madness are at least remotely believable.
In "Fight Club", we believe in the existence of Tyler Durden because he actually interacts with more people than just the main character. In "The Machinist", Ivan never interacts with anyone other than Trevor.
Later, when the foreman told Trevor that there was no such person as Ivan, I didn't feel any surprise. Instead I felt insulted. "Did they expect to catch me off guard with that? Of course he's not real!", I thought to myself. The film does nothing to lend any believability to Ivan's existence.
In the end, the film gives away the supposed twist with such obviousness, the only way they could possibly have surprised the audience would have been to reveal, at the end, that Trevor was in fact correct, that his boss, co-workers, escort, girlfriend, and Ivan were all actually conspiring against him.