Not sure why people mention Bruce....he was a great martial arts innovator and his influence in martial arts is legendary..........that said he was not really a combat sports competitor atleast not to the degree that his contempories were and likewise the same today.
Speaking of which, why didn't boxing ever take a strong foothold in a country China? 1 billion people with a rich martial arts tradition (Most of which are standup/striking arts)? One would think the Chinese would be all over boxing matches. With a billion people, there's gotta be a few Pacquiao's in that pool.