There's a reason why this movie has some negative reviews, or low score ratings. As a "boxing-only" movie, it fails to deliver unrealistic sequencies people tend to enjoy (like Rocky), or constant action filled with plot twists. Movie is simple, but this is not necessarily a bad thing. The movie's heart is a subtle message delivered through Eddie Brenan's fight agaisn't not only another boxer, but also, agaisn't time, failure and life. Eddie is a not so great man, with a no so great life. Not a big house, nor an important job. No purpose, no fate, only a man moving around and living day by day, without a goal and thus, without a sense of being. In some point of his life he started with boxing but age started to strike and with it, he started to fail and be left behind, with he being now recognized only when his descent is brought into conversation.
... however, he is all (heart). Eddie keeps standing up, keeps trying, keeps training, in an attempt to prove those who surround him, and more importantly, to prove himself, he has what it takes to make a fight, and win it (be it in a ring, or in his soul).
Movie is then a rollarcoaster of emotions when you deeply understand Eddie's character and what he is going through. With a realistic touch, from beginning to end.