Billy Hope is the undefeated light-heavyweight World Champion, however his life is thrown into chaos when his wife, Maureen (Rachael McAdams), is shot in a scuffle in a hotel lobby. He begins a downward spiral where his house and entire relationship with his daughter is under threat.
The transformation made by Jake Gyllenhall from gaunt Lou (from Nightcrawler) to Billy Hope whose better built than a tank showcases a hugely impressive level of dedication from an actor who often displays such levels of dedication to many roles. His impressive change in physique is, to extent, influenced by drugs, but it still required many hours in the gym to look convincing in the role. For Gyllenhall, the dedication was worth it because Southpaw is another fine display of his talents. Adopting a Marlon Brando esque mumble (so much so that he becomes hard to understand), Gyllenhall's performance in the film's more dramatic moments is moving and engaging and during the film's boxing sequences his physique is so impressive that he doesn't look remotely out of place.
The character of Billy Hope is a dividing one, he is a violent man participating in a violent sport so if he wasn't a successful boxer it'll be likely he'll be punching people in prison rather than in a ring. One can't help but feel that the removal of his custody rights to his child is the right thing to do, but Billy's genuinely loving relationship with his daughter is one of very few positive traits in his personality. It's this moving relationship and the great performances of Jake Gyllenhall and Oona Laurence (as his daughter) that helps the audience eventually side and become sympathetic to Billy when they have previously been swinging from sympathy to apathy as though they were riding the pendulum of empathy.
The film has an a good dramatic story which is more owed to some good leading performances rather than Antoine Fuqua's direction and Kurt Sutter's macho script that seemed to be missing something that would have helped the film deal with the progression of time better than it does However, the film's boxing sequences are electrifying and exciting due to some terrific editing that throws the audience right inside the ring.