When they defend the choke with committed hand fighting, take the arm they gave you: rotate off the back, leg over the head, and extend the defending arm — the classic RNC-armbar dilemma.
Submission · Armlock · Gi & No-gi · Difficulty 3/5 · Usually learned at Blue belt
Starts from Back Control as the back taker → ends the match (submission).
The details that make it work
Their two-on-one defense of your choking hand IS the isolation — hug that arm and rotate.
Your top leg swings over their head as your hips slide out to the perpendicular.
Keep the choke threat alive until the last moment; the dilemma is what finishes people.
Where it goes wrong
Abandoning the back early for a low-percentage arm, losing both.
How opponents counter it
Release the hand fight and re-square as the hips leave
Lock hands and stack the moment the rotation starts
Is the Armbar from Back Control legal in competition?
Legal in all major rulesets at all levels (IBJJF, ADCC, sub-only). Rules change — always confirm against the current official rulebook for your event.