“Rank doesn’t matter” is up there with “size doesn’t matter” with me. Or at least it has been as of late. Someone will make a comment about rank not mattering and I’ll rattle off a list of things that are rank dependent. In an ideal world, rank doesn’t matter. In the real world, rank can be everything.
The number one reason for rank mattering is competition. In both judo and BJJ, who you fight depends on what color is on your waist, but more importantly the techniques change. When I found out that even tournaments which have been allowing armbars at yonkyu won’t anymore I decided I’m not going to fight at judo competitions again until someone breaks down and gives me a brown belt. The fact that I, after five years and a BJJ blue belt, couldn’t use an armbar in competition disgusts me. In BJJ the legal submissions change.
The second thing rank is good for is privileges. For BJJ you can start teaching after blue or purple depending on your organization. In judo, brown is where you can start running open mat and get your reffing certification.
The final thing is perception. Suppose you’re in a gym with an advanced only class and you get two new students. One’s a white belt of five years who can rip the heads off your purple belts, but never got ranked. The other is a purple belt who earned it for showing up to class enough and has no competition experience. The purple belt says they want to start in the advanced class. They’re a purple belt, you don’t question it. The white belt? You evaluate him because of his rank – there has to be some reason he didn’t get ranked, right?
Likewise, gyms with black belt instructors can charge more than gyms with brown belt instructors. Even if the brown belt is a better coach, competitor, or fighter, he’s not a black belt. I see it all the time. In the minds of students, having a black belt matters.
So, no, relative to the other guys at your gym it doesn’t matter if you’re white and they’re blue. Having a blue belt won’t make you a better fighter. In the rest of the world where people can’t judge you by experience and where governing bodies control privileges within the art, you better believe that rank is the only thing you have to go on.