With a grip well outside shoulder width, hang freely from an overhead bar as you would doing a pull-up. This will be your starting position.
Instead of pulling yourself directly up to the bar, contract your lats to instead go in a counter-clockwise direction, pulling yourself partway up to the right side and continue going upward as you move back toward the center of the bar. Here your chin should meet the bar at the apex of the move.
Continue in a circular motion until you are back to the center, reaching full arm extension.
Complete for the designated number of reps in the same counter-clockwise motion. Because of the asymmetrical motion you'll repeat the move for the same number of reps going in a clockwise direction as well.