There are few topics as widely discussed as the meaning (and even the purpose) behind belt promotions (for some earlier grumblings by yours truly, see here and here). Standards vary from gym to gym just as they do from country to country. I have trained with young and hungry competitors in Brazil with white belts that would give some seasoned upper belts I have trained with here in the U.S. a run for their money (including me). I have also trained with high-level black belt competitors (who smashed or toyed with me) and more casual black belts (where I have had some mixed success). Just as the skill of those who hold various ranks varies from place to place, the standards for promotion vary as well.
Indeed, a good friend who recently spent some extended time on the mats with a fifth degree black belt (and former competitor) was told that if he were at another gym, he would be a brown (or even black) belt rather than a fourth degree purple belt. It was meant as (and taken to be) a compliment. But it was a compliment that also irked as it raised an important question: Just how arbitrary are promotions at the end of the day? They are clearly relative (which is to be expected). But are promotions grounded in anything above and beyond an instructor's subjective "feel"? Moreover, which instructor's feel should be trusted? After all, not all black belts are created equally and not all expert intuitions are equally informed by experience. So, what does it all mean?
Rather than worry about the progression at each level, for now I will focus on the progression from purple to brown--which is where I seem perpetually stuck (especially now that my neck is literally fixed and I am unable to train at a "live" pace). If white and blue belts are beginner's belts and purple belts are intermediate, the brown belt is the first belt of expertise. But expertise at what? Jiu jitsu, of course, but that's unhelpful. Must one be an expert at take downs and stand up? Must one be an expert at the various open guard systems--e.g., spider guard, X-guard, De Le Riva, etc.? Must one be an expert at self-defense? Must one know how to use and defend against leg locks?
Relatedly, must one be an expert instructor? If so, which techniques must one be able to teach (and what counts as excellence on this front)? Must one be a competitor? If so, do major tournaments count more than local tournaments? Compare winning a national (or even international) IBJJF event to winning a local or regional event. Clearly the former counts more than the latter, but how much more? If neither teaching nor competition are required, what stands in as a substitute for determinations of skill? Is it just live rolling with people in one's own gym that is to be the measure of success? If so, isn't that too narrow a body of information? And what happens when different instructors at the same gym (or the same affiliation) clearly have different subjective standards? How is that not supposed to raise hackles and questions of inequity and fairness? The only thing more frustrating than a moving target are targets that move differentially for different individuals. No wonder practitioners of jiu jitsu are left to mystery monger about promotions. They can seem unjustified or even arbitrary--with no obvious standards guiding the process.
These sorts of questions fuel the move towards a fixed and standard curriculum. Perhaps it's the professor in me, but I can't for the life of me figure out why a gym wouldn't have a fixed curriculum--one that makes explicit what is expected from someone at each belt level. It need not (and arguably) should not be so fine-grained as to explain when a student should get a stripe, but they should make it clear when someone is ready for a new belt. Lots of gyms rely on curricula--including some of the largest and most successful affiliations in the world (see here and here) as well as some local gyms (see here and here).
There are a multitude of reasons for having a curriculum. It removes the mystery from students, who now know what is expected of them if they are to make their way up the ranks. It regiments the whole promotion process and facilitates transparency. It also helps students learn because they know, at each step of their development, which skills and techniques they should be working on and which ones are to be developed later. It also benefits instructors. While designing a curriculum (and sticking to it) can be time consuming and onerous, once it's developed, a good curriculum can help instructors more productively structure their classes--since a clear line is drawn between fundamentals (white and blue belts) and advanced techniques (purple, brown, and black belts). Another benefit is that a well-thought-out curriculum can minimize the effects of nepotism, favoritism, etc. Once a curriculum is adopted, promotions no longer depend on "feel" but rather they depend on more tangible measures like: Do you know how to scissor sweep or shoot a double leg? Do you know how to use a cross collar choke? Do you know how to properly escape mount? Do you know how to use De La Riva and reverse De La Riva?
Obviously, not even a well developed and well planned curriculum can remove all relativity and subjectivity from the belt promotion process, but it goes on long way towards minimizing these problems. As such, I think it behooves instructors to adopt curricula. But what do I know, I am a lowly purple belt (at least at my gym).
p.s. For the record, my current gym does not use a curriculum--although I unsuccessfully argued early on that we should (see here). And I am most decidely not saying that a gym must have a curriculum in order to be a good gym. I have trained at a number of gyms without formal curricula that were great (including my present gym). But the points I make in this post still stand. Even if gyms can be run well without curricula it doesn't mean they wouldn't be improved with them! But here, as elsewhere, reasonable people can disagree.
p.p.s. For those inclined to disparage me for daring to express my opinion about these matters when I am just a lowly purple belt who has never run his own gym: I have trained jiu jitsu for nearly twelve years and I wrestled for an additional twelve years before that. Moreover, I have been teaching college since 2000. So, I write this post as a seasoned grappler and an experienced educator. If you nevertheless think I am unqualified to speak about pedagogy and jiu jitsu, I am happy to hash that out in the comment thread.