If you're not aware, Robert Drysdale is on e of the best in the world. If he's explaining his version of a submission, I'm listening carefully. You should too. This N-S choke is great - it's effective and usually very available. It does have plenty of nuance though - that is to say you could be in position and attempt it, but fail to get the tap (i.e., because the choke is not properly aligned on the throat). So work on it.
Now go adorn yourself in paper thin ripstop material, get a fauhawk and practice this move.
Props as always to GrapplerINFO for another great video.