For you to submit someone in jiujitsu, your game needs to exhibit—and excuse the shallow comparison here—the technology of a faucet.
Yes; after all, if the pipes and tubes are not in the right place, connected all the way to the source, and the stopcocks and other little pieces with obscure names are not in their positions, it's a no-go. However, if everything is in the right position, just turn your fingers and open the faucet gently, and poof—as if by magic, the water will flow in a refreshing stream.
That's what you can see, for example, in this lesson taught by Master Rickson Gracie about the kimura employed after passing the guard.
Learn how an imperfect base, a disconnection at the moment of the attack, and a distraction in the use of the knees and elbow can make the finish go, well, down the drain. This is just a snippet of the complete class that you will find in the Self.Defense.Unit section of our platform.