Aside from Rubingh, Woolgar and Gonbare, there are a slew of other high-level competitors, mostly from Russia or other Soviet provinces .
Nikolay "The Chairman" Sazhin currently holds the WCBA heavyweight and light-heavyweight championships, but he also held the WCBO light-heavyweight title from July 5, 2008, to Nov. 28, 2009. He was trained as a chess player in Russia, still fights as a heavyweight and has fought more than 100 bouts.
Sven Rooch of Moscow is a top middleweight, according to WCBO. He is a Berlin firefighter and trains in Berlin.
Armenian-born Dymer Agasaryan is the world middleweight and lightweight champion, but he's also a powerlifter, actor and model based in London.