Most jiu-jitsu students have heard “Position before Submission” at some point. As a general rule, when it comes to positional techniques, this is indeed true. Since its arguably one of the most important positions in BJJ, the Guard should be high on any student’s priority list.
Newer students always like to learn submissions first, because they are cool to do and give one a sense of power. However, the newer student’s focus should be to learn about Guard control and retention. Especially when dealing with someone bigger or more skilled.
Along with control and retention, having the ability to effectively sweep your opponent over onto their back, with you ending up on top, pays dividends. From this perspective, submissions would actually be second, or even third in line, on the list of things to do when you have Guard.
One more thing, if your opponent is escaping your submission attempt from Guard, or perhaps even passing your Guard, let that sub go and look to regain your control and retention again. Better to maintain control of a situation, and retain your Guard, then to give it up on something that isn’t working just for the sake of hitting that sub.
Learn. Drill. Roll. TRANSFORM!