Originally posted by Kyle
As a white-belt in BJJ, your job is to tap 
You are developing an awareness of the whole game. There is an emphasis on escapes, as that is the bedrock of BJJ. You can expect, with no previous grappling, to take 1 to 2 years to go from white to blue.
Also, technical knowledge is not skill. Each belt has a certain "look-and-feel" that refers to the skill in applying the techniques. Each instructor has their own preferred "look-and-feel". This is very difficult to put into words (i.e. "I can't describe it, but I know it when I see it").
- Kyle
I agree completely, especially the "look and feel" part. This is basically what I've been told:
Basically, as a white belt, you are learning familiarity with the different positions, and how it feels to be dominated in each one. Eventually you learn escapes and achieving positional dominance. "Your job is to tap" as you said, is spot on - at least in the beginning - if you are an advanced white, you may fare a little better.
As a blue, you will learn more techniques and set-ups. it varies by academy, but basically by the time you're ready to test for purple, you should know most of the techniques in the curicculum. Depending on your ability, you may begin to develop your submission skills at this point. Your escapes should be better. Your still getting by on your strength more than your technique, but that's changing.
As a purple, you begin to refine the techniques you learned at the previous 2 levels. You shouldn't learn too many new techniques here (other then the new stuff coming out of Rio, IF you or your instructor has access to it). You should be developing submissions now, and should be able to escape from most positions. Your balance and coordination should be noticeably better than the whites and blues.
As a brown, you should have refined your techniques to an expert level. You should be able to escape from many positions, and often in multiple ways. Your submission skills should be highly developed, and you should be able to target individual and specific areas effectively against most lower belts (i.e. work for a leglock on the left ankle), even if you tell them you are doing so. In terms of sheer technique, you should be extremely refined. if you are going to specialize in a certain area (say leg locks or chokes), you begin to develop those techniques even further, and can usually connect with them on someone close to your level. You may be developing the ability to think ahead a couple of moves.
As a black, the issue becomes more strategy than technique. Your techniques should have been perfected as a brown -- now you should be able to think 2, 3, or even 4 moves ahead and "set up" moves effectively. You should understand how subtle shifts in body positioning can make a big difference, and have an almost freaky sense of where you are in space, and what your opponent is doing. Your specialized areas should be developed at a very high level. You are comfortable fighting from every conceivable position, and know at least a couple of counters for almost anything thrown your way. You have also learned how to move with a minimum of wasted movement, so you are now using more technique than sheer strength. When people see you move, words like "powerful", "graceful", and "efficient" should spring forth from their lips.
As for higher levels of black belt, I have no idea -- perhaps you need to be able to turn water into wine or something
Obviously, you should be able to hold your own when you roll as well. As a blue belt you should beat most whites most of the time. As a purple most blues, etc. You really shouldn't ever lose to someone 2 belts below you (other than some freaky exceptions, like a national champion wrestler or judoka who is also a white belt or something).
