Quite a few things in martial arts that are claimed to be ancient are in fact turn of the century inventions by Kano Jigoro, the inventor of Judo: grades and belts, the keikogi uniform used by many martial arts today, etc.

Kano was all about modernizing what he saw as outdated and ineffective training techniques. He thought that by making jujitsu a sport he could save it from irrelevance, in an age when people where more likely to learn tennis than martial arts. He was very successful, he created Judo and some of his earlier students went on to develop BJJ.

> This ranking system was inspired by the existing Dan ranking system in Go, devised by Honinbo Dosaku in the late 17th century.

This is interesting, as a kyu go player I was aware of the relation to color belts in Judo, but I didn’t know it was the go ranks that inspired the judo ranks. I kind of always assumed it was the other way around.

Yeah, good job. Going from white to yellow I can kind of believe because of dirty hands and stuff. Kind of far fetched but I could buy it. But from that to orange to red to black just from dirty hands (especially red you would expect from the blood of your enemies) is just bs.