The modern offshore boat typically runs all halyards and control lines aft on the cabin house to stopper banks. Usually, the pit person has only two winches to handle eight or nine lines. With so many control lines and so few winches, it's inevitable that there will be times when you're short a winch. To utilize both winches most effectively, place a deck organizer aft of the stopper bank so lines can be routed to the far side winch. This is a common technique on custom boats which often lead the control lines straight aft to a stopper bank, but it can also be done very effectively on production boats that lead half of the controls down either side of the cabin house.
Organizers should have one more sheave than the number of control lines they will handle. Pass the lines between the sheaves so they can be turned to the winch on either side of the boat.
Choose your organizers with care. Boats to 15 m (40 ft) can generally use Midrange organizers. Controls like halyards often see very high loads because you are trying to tension fully-loaded sails, and bolt rope or luff tape friction can make it difficult to move the sail. Remember the load on the sheave is a factor of the load on the line, plus a factor determined by the angle of deflection — a sheave that turns a line 30 degrees sees only 52% of the load, while a sheave that turns a line 90 degrees sees 141% of the load.