I should really keep a journal of what I learn in the dojo. After all, the competent man must fight efficiently. Last week, I learned the basics of North/South.
The lesson was very interesting to me largely because I struggle with passing the guard. I can smash through someone's guard but I often get trapped in half as my partner snakes a foot back. My challenge stems from the fact that I have a game from side control but get lost if I move too far (i.e., north/south).
The basics of north/south: stay heavy -- imagine your pinned like a specimen to your partner and the floor. Catch a breath and smother your partner.
We also learned a basic submission. Get your partners hands to their stomach by sweeping your arms in and pinching your elbows towards their shoulder blades. Set up the kimura by grabbing a wrist and entangling the arm. Then force your partner onto their side, the side of the free arm. Bring your knees toward their shoulders (sit on their head if necessary), use the entangled arm as a pry, and keep the entangled elbow on your sternum. They'll move. As the come up onto their side, trap them by moving into s-mount. Make sure everything is perpendicular (you to your opponent, their forearm to their biceps, etc.). Then spiral your entire body to get the kimura submission.
That all sounds great but there are certainly some challenges. If their elbow comes off your sternum, the submission will be tough. If they grab their belt/gi to defend, spiral the other way to break their grip and then resume. If your angles are off or they've gabled their hands, spin and go for the arm bar. If they keep their hands clasped, try the biceps slicer. If they're really not moving, put some weight on their head or get their head between your ankles to feign the choke. Or, if none of that works -- my typical experience -- just scramble for a better position!
What to work on: I really have a terrible guard and I'm actually quite weak at passing. Both of these challenges may be due to grips. I've had some success with the left overhook while in guard. It sets up an entanglement of that arm which at the very least restricts my partner's mobility and gives me time to move my hips. As for passing the guard, I'm most weak at the mid-range attack. I need to go for either the double underhook or simply stand up and step around. The other option is to simply play very defensively and wait for them to be aggressive and give myself some time to breath.
Perhaps one way of interpreting fight efficiently is "fight is such a way so as to keep your breathing under control."