David Mamet is known for cooking up wild conspiracy-tinged plots (just look at "Spartan") and "Redbelt" is no exception:
Mike Terry (played by rising star Chiwetel Ejiofor) is a martial arts instructor who teaches his students realistic techniques for pure self-defense, not for sporting competition. His struggling dojo seems to finally catch a break as a chance encounter leads to a series of opportunities for both him and his wife, Sondra (Alice Braga in a role that mostly uses her looks and Brazilian descent). Things are more complicated than they seem, however...
Okay, I have to admit - "Redbelt" is pretty steeped in the world of Brazilian Jiu-jitsu and MMA competition, a world I know almost nothing about. But the philosophy of fighting presented in this movie is something that I am familiar with - the notion that sporting competition is not an accurate simulation of real world fighting (seriously, how many UFC matches are ended with one guy gouging the other guy's eyes out?), and that the real goal of a martial artist isn't funny-colored belts, money, or trophies, but principled and effective self-defense.