A putter has a center of gravity located rearward from the face and under
the stroking pivot point. The polar moment of inertia of the putter is
increased by moving the distribution of weight toward the rear of the
head away from the contact surface. The sole of the putter has an
optimized transverse radius and a raised front edge. The putter has an
aiming mark that has a minimum area and a minimum length-to-width ratio
and is brightly colored. The putter grip has a flat portion that is
oriented to match the player's hand rotational position. The face of the
putter has friction and energy transfer characteristics that are selected
to influence ball motion if struck with stroking errors. The face loft
angle cooperates with the face surface characteristics to influence ball
launch angle and rotation.