Matt Darcy shows his primary knee on belly escape. This is move 1 in the knee on belly escape system.
Matt Darcy shows how he uses the single leg to get to half guard when his opponent floats off of knee on belly to get away from the reversal.
Matt Darcy shows the second move in his knee on belly escape system. He goes to this move when he can't make space for the knee in the first move because his opponent is sitting their weight back toward their heel while in knee on belly.
Matt Darcy shows how he sets this move up by faking guard. He also shows how to swing back and forth to get the move when your opponent initially blocks it.