Some white belts develop a bad habit of tapping too late. And when I say too late, I’m not talking about once the joint has been injured or they start to go to sleep.
When you are not in a tournament or mma competition, you should tap before your partner gets 90% of the submission. So if you’re in an armbar, you should tap when your arm is at 160 degrees extension (in case your math is terrible, 90 degrees is when your arm is bent and makes an L shape, and 180 degrees is when your arm is straight.)
The problem with waiting until your arm is straight, for example, happens when you actually escape the armbar. You learn that last minute escapes, which often involve a lot of strength, work.
You teach yourself the wrong habit.
I have a student that has black belts in several other martial arts. I told him, “Prevention the submission is way better than escaping. The problem is not that I got the armbar, it’s that your elbow was away from your body when I was in a position to get the armbar.”
For several weeks after that, whenever he would roll he would put tennis balls in his armpits and just work his defense (you can use socks if you want). Every time he dropped one of the tennis balls, he knew that he was giving his partner the opportunity to submit him easier. If someone started to go for an arm or shoulder lock, he would tap. He knew that the submission started with him leaving his elbow away from his body.
Now when I train with this student, it is really difficult to get him in an arm or shoulder lock!
This is the benefit of rolling with black belts. If you are trying to escape the mount and you grab their chest and start pushing, you’re going to get armbarred. You learn that pushing your partner off is a bad idea.
If you did that with another white belt, they probably won’t armbar you. You may even get out. You learn that dong the wrong thing works.
Having the discipline to tap early will prevent you from developing bad habits. You’ll tap more now, and a lot less later.