A pro fighter faces the most difficult decision of his life when contemplating the prospect of retirement. Unfortunately, too many hang on well past the time when they can compete at the highest level only serving to diminish their legacy and damage their health. MMA is no different than boxing in this respect, and following his brutal knockout loss to Melvin Manhoef at DREAM 4 Japan's legendary Kazushi Sakuraba appears to fit the description of a fighter who needs to call it quits but is unwilling to do so.

Mixed martial arts is booming in America, but there's not one specific fighter responsible for its upswing in popularity. That's not the case in Japan, as Sakuraba is almost universally acknowledged as having brought MMA to the mainstream of Japanese sports and popular culture. In particular, his on-going feud with Brazil's Gracie family made him a major superstar and national hero.

While Sakuraba's resume certainly justifies the reverence with which hes held by the Japanese fight community, hes not really done anything to build on that legacy for several years. His last truly significant victory was a submission win over former UFC light heavyweight champ Quinton Rampage Jackson and his last victory over what can be considered a quality opponent in his prime was against Kevin Randleman in late 2003.

Boxing pundits frequently speak of a fighter's age in terms of 'ring years'. For that reason a younger fighter who has endured a series of grueling fights against high level opponents can be considered 'old in ring years', while an older fighter who has taken an easier path is considered 'young' by the same metric. Under this evaluation, there's no doubt that Sakuraba has to be considered old in 'ring years'. His 90 minute battle with Royce Gracie alone took a significant toll on Sakuraba, and he continued to face high level opponents after that.

Furthermore he'd frequently find himself across the ring from much larger superstars, his popularity and fearlessness producing matchups that could never get sanctioned in the US but are commonplace in the wild wild west environment of Japanese fighting. The quality of opposition he faced is staggering"Royce Gracie and several other members of the legendary family, Wanderlei Silva, Mirko Cro Cop, Vitor Belfort, and Antonio Rodrigo Nogueira stand out as the most impressive names on his record. Unfortunately and not surprisingly, he had difficulty when stepping up in class against heavier fighters and most of these matchups resulted in losses by brutal knockout or other type of stoppage.

Sakuraba has been less active in the past couple of years, but has shown little indication that he'll formally retire. Hopefully this decision won't undermine his legacy or more importantly negatively impact his long term mental and physical health.