Relative position between center of gravity and hit center in a golf club

A method of designing a golf club, the method comprising:

• defining a space relative to a point of contact for a ball on a face of a golf club head of the golf club regardless of the orientation of the golf club head;
• selecting parameter values for a golf club head that determine a position for the center of gravity for the golf club head;
• determining if the center of gravity is within the defined space when the face of the club head contacts the ball during a swing of the golf club;
• and
• if the center of gravity is not within the defined space, selecting new parameter values for the golf club head that determine a new position for the center of gravity for the golf club head until the center of gravity for the golf club head falls within the defined space when the club head contacts the ball during a swing of the golf club.

A left-handed golf club comprising:

• a shaft;
• a golf club head comprising:
• a hosel accepting a part of the shaft;
• a portion of the shaft comprising the part of the shaft in the hosel and two inches of shaft extending out of the hosel;
• a center of gravity;
• and
• a face having a hit center that is one of a set consisting of a hit center indicated by markings on the face as being a point preferred over all other points on the club for contacting the ball and a hit center that is the same as a face center of the face, the hit center defining an origin of an impact reference frame having X, Y and Z axes defined based on swinging the golf club about a swing axis along a swing plane that is angled to a surface, wherein the Y axis is defined as a normal to the surface, the Z axis is defined as a normal to a plane orthogonal to the surface and containing the center of gravity at a bottom of the swing and the swing axis, and the X axis is defined as being orthogonal to the Y axis and Z axis and parallel to the surface and wherein space above the origin is in a positive Y direction, space below the origin is in a negative Y direction, space behind the origin is in a negative Z direction, space in front of the origin is in a positive Z direction, space to the left of the origin when viewing from a negative Z position to a positive Z position is in a positive X direction and space to the right of the origin when viewing from a negative Z position to a positive Z position is in a negative X direction;
• wherein the center of gravity is positioned relative to the hit center such that when the hit center impacts a ball during a swinging of the golf club along a swing plane angled between 40 and 60 degrees to the surface with the face oriented for maximum distance, where distance is the sum of flight and bounce and roll distance as measured by the X and Z coordinates of the ball stop point in the impact reference frame, the center of gravity is positioned in a space defined as a partial ellipsoid described as those points P satisfying:
• (
• (
• 0.836
• 
• 
• P
• x
• +
• 0.501
• 
• 
• P
• y
• -
• 0.224
• 
• 
• P
• z
• +
• 0.492
• 0.64
• )
• 2
• +
• (
• -
• 0.549
• 
• 
• P
• x
• +
• 0.763
• 
• 
• P
• y
• -
• 0.341
• 
• 
• P
• z
• -
• 0.075
• 0.42
• )
• 2
• +
• (
• 0.408
• 
• 
• P
• y
• +
• 0.913
• 
• 
• P
• z
• +
• 3.166
• 2.90
• )
• 2
• )
• ≤
• 1
• where Px, Py, and Pz are the X, Y, and Z coordinates, respectively, of a point P in inches from the hit center origin of the impact reference frame and where 0.408Py+0.913Pz+3.166≧0.