When going for the north south reversal, the main reaction will be for the opponent to rip out the arm that is being trapped to prevent their post. When this happens it creates enough space to be able to regain a guard.
Matt Darcy shows a north south reversal by swinging into a side control position. By wrapping his arm around the top opponents head he traps their arm as well and prevents the post when he rolls.
Matt Darcy shows how to force your opponent to make a mistake when trying to hold you in side control. The under hook hand position sometimes forces a headlock to prevent you from taking their back. We all know the headlock is terrible technique and we should then capitalize on it.
Matt Darcy shows how to use the under hook hand position to make your opponent make mistakes. You then can capitalize with a butterfly guard back take.