Written by Kurt Sutter (known for the TV show "Sons of Anarchy"), its a lazy script with nothing new to bring to the genre (except the plot device that sets the story in motion). Director Antoine Fuqua tries to bring "street cred" to the story with gritty dark visuals and Eminem rapping the title song, but it all feels fake and a constant retread of a story told many times.
Rachel McAdams plays "Mo", Billy's wife in what amounts to a cameo. Their daughter, played by newcomer, Oona Laurence is a 10 year old bore who, unfortunately, can't hold her own in her scenes with Mr. Gyllenhaal. Curtis "50 Cent" Jackson is the stereotypical manager who turns on his fighter the minute he smells a better deal. And Mr. Whitaker, an actor with a quality pedigree walks through his role as the trainer using "Mickey" from the "Rocky" movies as his role model.
There are so many contradictions, I don't know where to begin and the climatic fight, while very realistic, just doesn't produce the same excitement as so many other "fight" films. What holds the film together is the committed performance by Mr. Gyllenhaal. His physical and emotional performance rises above the material and he's a winner, even if the film isn't.