So after you've taken the back, and you have a back mount position with an over-under clinch, sometimes, you might fall to what is called the "weak side".
Let's rewind for a second, here. So the over-under clinch means you have one arm (let's say your right arm), over their (right) shoulder, and the other arm (your left arm) under their (left) arm. Both your hands are clamped together, pressing against their body.
So the "weak" side is the underhook side, which, in our example, is the left side. There's an issue here, in trying to do the Rear Naked Choke - your left arm is trapped!! So, we have to go through a process of freeing that arm, with minimal chance of them escaping.
What we do is we bring our right arm under their neck to grab their shoulder and pull them up... also, you use your right leg (which is hooked inside their right leg), and pull their leg back at the same time of pulling their shoulder up. This increases the possibility of moving them enough to get your arm out.
Now that you're able to move them enough to get your arm out, slide your left arm UNDER your right arm, which crossed their neck to grab the shoulder, and let them drop into your left arm. This way, there is no gap in the transfer.
From there, your left arm grabs your right bicep, your right arm adjusts their chin to line up with your (left) elbow, then your right hand enters behind their neck with the palm facing towards you (so they can't pull it down), then you turn your palm onto their head, and squeeze with your left arm.
Partners, make sure to tap, and people doing the technique, make sure to please release the grip after they tap.
Please exercise great safety and caution when training this technique.
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