This doesn't directly answer your question, but instead of thinking about the missed 4 points, consider the opportunity for a submission. Pick one that you're good at from guard (triangle, guillotine, armbar, kimura, but not americana) and start setting it up before you get rolled. Finish as he comes up on top.
I like working one leg high to set up the triangle, but left elbow to his left (or right to right) shoulder to set up the kimura also works nicely for me. Going straight for a one armed guillotine from mount gives you a good opportunity to sink it in tighter as he bridges. For armbar grab his right elbow with your right hand (or left with left), and palm his left ear with your left hand (or right with right) to have the armbar waiting for you on the bottom.
Going for americana from mount is a waste, you're just giving them a free bridge, and odds of finishing it are miniscule.