Refer to figure.
A fully articulated rotor head design permits some increase in control power by mounting the flapping hinges outboard of the hub. These are known as "offset flapping hinges". When the flapping hinges are at some distance from the hub, the hub and shaft effectively form a rigid T shaped structure. The rotor blades are attached to this rigid "T".

When they are rotating, a couple is produced by the components of centrifugal force. This couple acts to align the "T" of the hub and shaft with the rotor. In other words, it tends to drive the fuselage back into alignment with the rotor, i.e. drives the mast back to the equilibrium position. This couple combines with the horizontal component of the Total Rotor Thrust to enhance control effectivenes, increase control power and improve static stability, by increasing aerodynamic damping. Additionally, it reduces the stresses on the rotor system by achieving flapping with smaller pitch changes.