Agrega una trama en tu idiomaTHE PROVING GROUNDS is an all-access inside look at what goes on at Jackson's MMA academy. Get to know Greg Jackson and the family. Learn about the strategies, philosophies, history, and har... Leer todoTHE PROVING GROUNDS is an all-access inside look at what goes on at Jackson's MMA academy. Get to know Greg Jackson and the family. Learn about the strategies, philosophies, history, and hardships behind the best MMA school in the world.THE PROVING GROUNDS is an all-access inside look at what goes on at Jackson's MMA academy. Get to know Greg Jackson and the family. Learn about the strategies, philosophies, history, and hardships behind the best MMA school in the world.