Overstable discs turn with the rotation of the spin. When a right hand back hand thrower throws a disc it will have a counter clockwise rotation causing the disc to finish to the left. These discs will usually finish left when thrown with no or little wind. When there is a stronger wind, the overstable discs will go straighter for longer before turning left. Overstability combined with stronger fades combine to make a very strong finishing disc which is often the most predictable disc in your bag.