North south is probably the hardest pin to escape, because your legs are the farthest from his legs, so it’s hard to get your guard back. I’d look at it from a reverse perspective.
The easiest thing to do is to stop him from sinking a solid pin on side control(prevent tight pin). The next easiest is to stop him from getting to north/south from side control. If he’s solidly on north/south, the next easiest is to just move yourself back under side control.
Preventing a tight pin
As he passes your guard, use your arms to stop him from grabbing your head or especially hooking his arm over your far shoulder.
Check out this video on Marcelo Garcia’s sit up escape and elbow push escape:
If you’re doing this kind of stuff right, you’ll escape before they lock in a deep pin.
Preventing side control-> north/south
But let’s say you’ve failed at that. He’s hooked his arm over your far shoulder and is blocking your near hip and is circling around to north/south.
Walk your feet in a circle with him so he never gets to north/south; he just stays on top of side control. If he is blocking your near hip with his arm, pop your hips up in the air a little bit to lift his arm up a little bit so you have freedom to keep circling. You don’t want his hips to come over your head, so use your arms to redirect his force outward as you both circle. Try to keep both of your hands on one side of his body so you can push him outward. If you have one arm on each side of his body, you’re going to be stuck under north south and probably open to the paper cutter choke.
Escaping north/south by getting back under side control
Let’s say you failed at that and he’s got a solid north/south. Obviously, keep your arms in tight posture. Don’t allow his hips to come over your face; he should always be on one side or the other of your head. Keep your face turned towards whichever side his hips are on. He needs you to look away from him to do the north south guillotine, and it also helps a lot for the armbar, kimura, and paper cutter. Walk your feet in a circle so you’re back under side control. If he circles with you, abruptly switch directions and go the other way, so you’re under side control on the other side.
Here are two escapes from Marcelo Garcia that pretty much line up with what I said earlier.
North south escape using elbow push vs side control
Get both your arms on one side of his body, work your way back to under side control and escape from there.
One reason this is good is that the ‘escape’ (walk back to under side control) is the same as the prevention when he’s on side control and trying to go to north south (walk to keep yourself under side control). So there’s a seamless transition between escape and prevention.
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