Golf club heads

Abstract

Golf club heads are provided for selectively increasing or optimizing the coefficient of restitution (COR) at likely impact locations on the striking face of the golf club heads, while simultaneously maintaining characteristic time (CT) below a threshold value in those likely impact locations. By analyzing historical impact locations of a large cross-section of golfers, golf club head COR values can be increased or optimized in preferential locations on the striking face, such as using weighting factors for a predefined set of locations on the striking face. Therefore, instead of increasing COR uniformly across the face and/or increasing COR at impact locations on the face where golfers are unlikely to strike the golf ball, the sweet spot of the golf club head can be increased at the impact locations where golfers typically strike the golf ball.

1 - 20 . (canceled) 
     
     
         21 . A golf club head comprising:
 a body defining an interior region, the body comprising a sole portion, a crown portion, a skirt portion, a front portion comprising a strike face having a variable face thickness profile, a heel opening configured to receive a fastening member, a head-shaft connection system including a sleeve that is secured by the fastening member in a locked position, the head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions resulting in an adjustability range of different combinations of loft angle, face angle, or lie angle;   wherein:   a geometric center of the strike face defines an origin defining a coordinate system having multiple orthogonal axes, including an origin x-axis extending tangential to the strike face and parallel to a ground plane when the golf club head is at an address position, an origin y-axis extending perpendicular to the origin x-axis and parallel to the ground plane when the golf club head is at the address position, and an origin z-axis perpendicular to both the origin x-axis and the origin y-axis;   the golf club head has a center-face y-axis location (CFY) of 11-16 mm;   the golf club head has a face progression (FP) of 10-19 mm;   the golf club head has a volume of at least 300 cc, a body length of at least 103 mm, a moment of inertia about a CG x-axis (Ixx) of at least 280 kg·mm 2 , a moment of inertia about a CG y-axis (Iyy) is at least 275 kg·mm 2 , a moment of inertia about a CG z-axis (Izz) of at least 450 kg·mm 2 , a golf club head mass of 185-210 grams, and a center of gravity whose location is defined relative to the origin via a CGx coordinate, a CGy coordinate, and a CGz coordinate of less than −2.5 mm, the center of gravity location is at a Zup elevation, and a peak crown height of at least two times greater than the Zup elevation, and a Delta1 distance of at least 15 mm;   the strike face has a balance point coefficient of restitution (COR) of at least 0.820-0.840;   the strike face comprises a central region defined by a 40 millimeter (mm) by 20 mm rectangular area centered on the geometric center of the strike face, wherein the central region is elongated in a heel-to-toe direction, and within the central region the strike face has a face thickness that varies with a minimum central region thickness of less than 2.5 mm and a maximum central region thickness of less than 3.3 mm;   the strike face comprises a first coefficient of restitution weighting factor and a first COR value positioned on the strike face at the geometric center of the strike face corresponding to an (x, y) coordinate of (0, 0);   the strike face comprises a second COR weighting factor and a second COR value positioned on the strike face 10 mm above the geometric center of the strike face corresponding to an (x, y) coordinate of (0, 10);   the strike face comprises a third COR weighting factor and a third COR value positioned on the strike face 10 mm below the geometric center of the strike face corresponding to an (x, y) coordinate of (0, −10);   the strike face comprises a fourth COR weighting factor and a fourth COR value positioned on the strike face 20 mm toe-ward of the geometric center of the strike face corresponding to an (x, y) coordinate of (−20, 0);   the strike face comprises a fifth COR weighting factor and a fifth COR value positioned on the strike face 20 mm heel-ward of the geometric center of the strike face corresponding to an (x, y) coordinate of (20, 0);   the first COR weighting factor is 0.3267, the second COR weighting factor is 0.2256, the third COR weighting factor is 0.1395, the fourth COR weighting factor is 0.2263, and the fifth COR weighting factor is 0.0819;   a summation of the first, second, third, fourth, and fifth COR weighting factors is 1;   the first COR value is no less than 0.817, the second COR value is no less than 0.801, the third COR value is no less than 0.775, the fourth COR value is no less than 0.785, and the fifth COR value is no less than 0.720; and   a weighted COR value is 0.804-0.820, the weighted COR value comprising a summation of:
 the first COR weighting factor multiplied by the first COR value, 
 the second COR weighting factor multiplied by the second COR value, 
 the third COR weighting factor multiplied by the third COR value, 
 the fourth COR weighting factor multiplied by the fourth COR value, and 
 the fifth COR weighting factor multiplied by the fifth COR value. 
   
     
     
         22 . The golf club head of  claim 21 , wherein:
 the balance point COR is at least 0.822;   the peak crown height is no more than 70 mm;   the body comprises a front body portion including a forward sole portion, a forward heel portion, and a forward toe portion, wherein the front body portion extends at least 20 mm rearward of the origin measured parallel to the origin y-axis; and   the golf club head has a rear mass element attached to the golf club head and having a rear mass element mass of at least 5 grams, wherein the rear mass element has a rear mass element y-axis coordinate of 90-120 mm, and a rear mass element z-axis coordinate of −30 mm to 10 mm.   
     
     
         23 . The golf club head of  claim 22 , wherein the weighted COR value is 0.805-0.813, the face progression (FP) is less than 18 mm, the front body portion forms a face opening, the strike face comprises a strike plate closing the face opening, and the front body portion is formed of a front body portion material comprising at least one of a titanium alloy, an aluminum alloy, a steel alloy, or a magnesium alloy. 
     
     
         24 . The golf club head of  claim 23 , wherein a first center face CT is no more than 257 s, and the weighted COR value is at least 0.806. 
     
     
         25 . The golf club head of  claim 24 , wherein a first maximum characteristic time (CT) within the central region is less than 257 s, and the weighted COR value is at least 0.807. 
     
     
         26 . The golf club head of  claim 25 , wherein the rear mass element mass is at least 10 grams, the rear mass element y-axis coordinate is at least 110 mm, the balance point COR is at least 0.829, the moment of inertia about the CG x-axis (Ixx) is at least 300 kg·mm 2 , the moment of inertia about the CG z-axis (Izz) is at least 500 kg·mm 2 , and the Delta1 distance is at least 20 mm. 
     
     
         27 . The golf club head of  claim 25 , wherein the rear mass element mass is at least 15 grams, the rear mass element y-axis coordinate is at least 110 mm, at least a portion of the crown portion comprises one or more fiber reinforced polymer materials, the moment of inertia about the CG x-axis (Ixx) is at least 350 kg·mm 2 , the moment of inertia about the CG z-axis (Izz) is at least 525 kg·mm 2 , the Delta1 distance is at least 24 mm, and a ratio of Ixx to Izz is greater than 0.7, and a roll curvature is between 0.033 cm −1  and about 0.066 cm −1 , and a bulge curvature is greater than 0 and less than about 0.027 cm −1 . 
     
     
         28 . The golf club head of  claim 25 , wherein at least a portion of the crown portion comprises one or more fiber reinforced polymer materials, and the volume is at least 420 cc. 
     
     
         29 . The golf club head of  claim 28 , wherein the balance point COR is at least 0.829, the moment of inertia about the CG x-axis (Ixx) is at least 300 kg·mm 2 , the moment of inertia about the CG z-axis (Izz) is at least 500 kg·mm 2 , and the Delta1 distance is at least 20 mm. 
     
     
         30 . The golf club head of  claim 29 , wherein the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness. 
     
     
         31 . The golf club head of  claim 28 , wherein the balance point COR is at least 0.830, the Zup elevation is no more than 25 mm, and the CGz coordinate is less than −3.5 mm. 
     
     
         32 . The golf club head of  claim 31 , wherein the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.8 mm greater than the minimum face thickness. 
     
     
         33 . The golf club head of  claim 28 , wherein strike plate is formed of a strike plate material that is different than the front body portion material, the strike face comprises a variable face thickness profile that is non-symmetrical, and the rear mass element has a rear mass element x-axis coordinate of −20 mm to 10 mm. 
     
     
         34 . The golf club head of  claim 33 , wherein the strike face has a maximum face thickness and a minimum face thickness, the maximum face thickness is at least 1.0 mm greater than the minimum face thickness, and at least a portion of the crown portion comprises polysulfone. 
     
     
         35 . The golf club head of  claim 21 , wherein the body comprises a front body portion including a forward sole portion, a forward heel portion, and a forward toe portion, wherein the front body portion extends at least 20 mm rearward of the origin measured parallel to the origin y-axis, and the front body portion is formed of a front body portion material comprising aluminum alloy. 
     
     
         36 . The golf club head of  claim 35 , wherein the balance point COR is at least 0.822, the face progression (FP) is less than 18 mm, the front body portion forms a face opening, and the strike face comprises a strike plate closing the face opening and formed of a strike plate material that is different than the front body portion material. 
     
     
         37 . The golf club head of  claim 36 , wherein a first center face CT is no more than 257 s, and the weighted COR value is 0.805-0.813. 
     
     
         38 . The golf club head of  claim 37 , wherein the weighted COR value is at least 0.806. 
     
     
         39 . The golf club head of  claim 37 , wherein the weighted COR value is at least 0.807, and the balance point COR is at least 0.829. 
     
     
         40 . The golf club head of  claim 37 , further comprising a rear mass element attached to the golf club head and having a rear mass element mass of at least 5 grams, wherein the rear mass element has a rear mass element y-axis coordinate of 90-120 mm, and a rear mass element z-axis coordinate of −30 mm to 10 mm. 
     
     
         41 . The golf club head of  claim 40 , wherein the rear mass element y-axis coordinate is at least 110 mm, the moment of inertia about the CG x-axis (Ixx) is at least 300 kg·mm 2 , the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness. 
     
     
         42 . The golf club head of  claim 40 , wherein the body comprises an aft body attached to the front body portion, the aft body comprising a rearward crown portion and a rearward sole portion, at least a portion of the rearward crown portion comprises one or more fiber reinforced polymer materials, the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.8 mm greater than the minimum face thickness. 
     
     
         43 . The golf club head of  claim 40 , wherein the rear mass element mass is at least 10 grams, the rear mass element y-axis coordinate is at least 110 mm, the rear mass element has a rear mass element x-axis coordinate of −20 mm to 10 mm, the moment of inertia about the CG x-axis (Ixx) is at least 350 kg·mm 2 , the moment of inertia about the CG z-axis (Izz) is at least 525 kg·mm 2 , the Delta1 distance is at least 24 mm, and a ratio of Ixx to Izz is greater than 0.7. 
     
     
         44 . The golf club head of  claim 37 , wherein the golf club head has a face-back dimension defined as the distance between a hypothetical plane, passing through the face center and parallel to the strike face, and a rearmost point on the golf club head in a face-back direction perpendicular to the hypothetical plane, wherein face center is located at 0% of the face-back dimension and the rearmost point is located at 100% of the face-back dimension, and the golf club head is divided into a face section that extends, in the face-back direction, from 0% of the face-back dimension to 25% of the face-back dimension, a middle section that extends, in the face-back direction, from 25% to 75% of the face-back dimension, and a back section that extends, in the face-back direction, from 75% to 100% of the face-back dimension, and wherein no more than 20% by weight of the middle section is made of a material having a middle section density of 4.0 g/cc and 20.0 g/cc. 
     
     
         45 . The golf club head of  claim 44 , wherein the front body portion has a plate-opening recessed ledge, and the strike plate is adhesively bonded to the plate-opening recessed ledge. 
     
     
         46 . The golf club head of  claim 45 , wherein the front body portion extends no more than 70 mm rearward of the origin measured parallel to the origin y-axis. 
     
     
         47 . The golf club head of  claim 45 , wherein at least a portion of the sole portion comprises one or more fiber reinforced polymer materials, the strike face comprises a variable face thickness profile that is non-symmetrical, the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness. 
     
     
         48 . The golf club head of  claim 21 , wherein:
 the body comprises a front body portion forming a face opening and extending 20-70 mm rearward of the origin measured parallel to the origin y-axis, the front body portion having (a) a hosel portion with a hosel bore defining a shaft axis and a shaft axis plane, (b) a first front body portion formed of a first front body material and having a first front body portion mass, and a first front body portion density, and forming a portion of the face opening, and (c) a second front body portion formed of a second front body material having a second front body portion mass and a second portion density greater than first portion density, and forming a portion of the sole portion and a portion of a leading edge of the golf club head; and   the strike face comprises a strike plate insert closing the face opening, the strike plate is formed of a strike plate material that is different than at least one of the first front body material and the second front body material, and the strike plate has a strike plate mass.   
     
     
         49 . The golf club head of  claim 48 , wherein the weighted COR value is 0.805-0.813, the face progression (FP) is less than 18 mm, and a sum of the first front body portion mass and the second front body portion mass is 47.7-109.1 grams. 
     
     
         50 . The golf club head of  claim 49 , wherein the balance point COR is at least 0.822, and the moment of inertia about the CG x-axis (Ixx) is at least 300 kg·mm 2 . 
     
     
         51 . The golf club head of  claim 50 , wherein the balance point COR is at least 0.829, the weighted COR value is 0.806-0.812, the moment of inertia about the CG z-axis (Izz) is at least 500 kg·mm 2 , the Delta1 distance is at least 20 mm, the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness. 
     
     
         52 . The golf club head of  claim 49 , wherein the balance point COR is at least 0.822, the weighted COR value is at least 0.806, a first maximum characteristic time (CT) within the central region is less than 257 s, and the second front body portion mass is at least 23.9 grams. 
     
     
         53 . The golf club head of  claim 52 , further including a rear mass element attached to the golf club head and having a rear mass element mass of at least 5 grams, wherein the rear mass element has a rear mass element y-axis coordinate of 90-120 mm, and a rear mass element z-axis coordinate of −30 mm to 10 mm. 
     
     
         54 . The golf club head of  claim 53 , wherein the weighted COR value is at least 0.807, the rear mass element y-axis coordinate is at least 110 mm, the balance point COR is at least 0.829, the first front body material comprises aluminum alloy, at least a portion of the crown portion comprises one or more fiber reinforced polymer materials, the second portion density is at least 7.8 g/cc, and the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness. 
     
     
         55 . The golf club head of  claim 49 , wherein the second front body portion forms a portion of the face opening. 
     
     
         56 . The golf club head of  claim 22 , further including a front mass element attached to the front body portion and having a front mass element mass that is different than the rear mass element mass, and the weighted COR value is at least 0.806. 
     
     
         57 . The golf club head of  claim 56 , wherein the weighted COR value is at least 0.807, the balance point COR is at least 0.822, and the strike face comprises a variable face thickness profile that is non-symmetrical. 
     
     
         58 . The golf club head of  claim 57 , wherein the variable face thickness profile is offset toe-ward of the geometric center of the strike face, the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness. 
     
     
         59 . The golf club head of  claim 56 , wherein the weighted COR value is 0.807-0.813, the moment of inertia about the CG z-axis (Izz) is at least 500 kg·mm 2 , the moment of inertia about a CG x-axis (Ixx) of at least 300 kg·mm 2 , the Delta1 distance is at least 20 mm, and at least a portion of the crown portion comprises one or more fiber reinforced polymer materials. 
     
     
         60 . The golf club head of  claim 59 , wherein the balance point COR is at least 0.822, the moment of inertia about the CG z-axis (Izz) is at least 525 kg·mm 2 , the moment of inertia about a CG x-axis (Ixx) of at least 350 kg·mm 2 , the Delta1 distance is at least 22 mm, a ratio of Ixx to Izz is greater than 0.7, and the volume is at least 420 cc. 
     
     
         61 . The golf club head of  claim 60 , wherein the balance point COR is at least 0.829, a first maximum characteristic time (CT) within the central region is less than 257 s, the Delta1 distance is at least 26 mm, the strike face has a maximum face thickness and a minimum face thickness, and the maximum face thickness is at least 0.6 mm greater than the minimum face thickness, the second COR value is at least 0.807, the first COR value is no more than 0.840, a difference between the third COR value and the fifth COR value is 0.004-0.085, a difference between the second COR value and the fourth COR value is 0.007-0.060, the fourth COR value is greater than the fifth COR value, the second COR value is greater than the third COR value, and the fourth COR value is no more than 0.815. 
     
     
         62 . The golf club head of  claim 59 , wherein the front mass element and the rear mass element are interchangeable, one of the front mass element mass and the rear mass element mass is 15-35 grams, one of the front mass element mass and the rear mass element mass is 10 grams or less, and each of the front mass element, the rear mass element, and the fastening member are configured to be engaged by a common tool. 
     
     
         63 . The golf club head of  claim 62 , wherein the golf club head has a face-back dimension defined as the distance between a hypothetical plane, passing through the face center and parallel to the strike face, and a rearmost point on the golf club head in a face-back direction perpendicular to the hypothetical plane, wherein face center is located at 0% of the face-back dimension and the rearmost point is located at 100% of the face-back dimension, and the golf club head is divided into a face section that extends, in the face-back direction, from 0% of the face-back dimension to 25% of the face-back dimension, a middle section that extends, in the face-back direction, from 25% to 75% of the face-back dimension, and a back section that extends, in the face-back direction, from 75% to 100% of the face-back dimension, and wherein no more than 20% by weight of the middle section is made of a material having a middle section density of 4.0 g/cc and 20.0 g/cc. 
     
     
         64 . The golf club head of  claim 63 , wherein the peak crown height is located in the middle section, and the rear mass element is located in the back section. 
     
     
         65 . The golf club head of  claim 63 , wherein the front mass element having a front mass element y-axis coordinate of 10-30 mm, and a front mass element z-axis coordinate of −30 mm to 10 mm. 
     
     
         66 . The golf club head of  claim 65 , wherein at least a portion of the crown portion comprises polysulfone. 
     
     
         67 . The golf club head of  claim 65 , wherein the front mass element has a front mass element x-axis coordinate, the rear mass element has a rear mass element x-axis coordinate, and the front mass element x-axis coordinate is greater than the rear mass element x-axis coordinate. 
     
     
         68 . The golf club head of  claim 67 , wherein the front mass element x-axis coordinate is no more than 35 mm, and the rear mass element has a rear mass element x-axis coordinate of −20 mm to 10 mm. 
     
     
         69 . The golf club head of  claim 67 , wherein a portion of the front mass elements is located more heelward than a portion of the heel opening. 
     
     
         70 . The golf club head of  claim 23 , wherein the strike face is formed from an alloy with an ultimate tensile strength of at least 958 MPa and having a maximum face thickness and a minimum face thickness, the maximum face thickness is at least 0.6 mm greater than the minimum face thickness, and the minimum face thickness is less than 2.20 mm. 
     
     
         71 . A golf club head comprising:
 a body defining an interior region, the body comprising a sole portion, a crown portion, a skirt portion, a front portion comprising a strike face having a variable face thickness profile having a maximum face thickness that is at least 0.6 mm greater than a minimum face thickness, a heel opening configured to receive a fastening member, a head-shaft connection system including a sleeve that is secured by the fastening member in a locked position, the head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions resulting in an adjustability range of different combinations of loft angle, face angle, or lie angle;   wherein:   a geometric center of the strike face defines an origin defining a coordinate system having multiple orthogonal axes, including an origin x-axis extending tangential to the strike face and parallel to a ground plane when the golf club head is at an address position, an origin y-axis extending perpendicular to the origin x-axis and parallel to the ground plane when the golf club head is at the address position, and an origin z-axis perpendicular to both the origin x-axis and the origin y-axis;   the golf club head has a center-face y-axis location (CFY) of 11-16 mm;   the golf club head has a face progression (FP) of 10-19 mm;   the golf club head has a volume of at least 300 cc, a body length of at least 103 mm, and a golf club head mass of 185-210 grams;   the body comprises a front body portion including a forward sole portion, a forward heel portion, and a forward toe portion, wherein the front body portion the front body portion forms a face opening and extends at least 20 mm rearward of the origin measured parallel to the origin y-axis, and the front body portion is formed of a front body portion material comprising aluminum alloy;   at least a portion of the crown portion comprises one or more fiber reinforced polymer materials;   the strike face comprises a strike plate adhesively bonded to the front body portion and closing the face opening and formed of a strike plate material that is different than the front body portion material;   the golf club head has a face-back dimension defined as a distance between a hypothetical plane, passing through the face center and parallel to the strike face, and a rearmost point on the golf club head in a face-back direction perpendicular to the hypothetical plane, wherein face center is located at 0% of the face-back dimension and the rearmost point is located at 100% of the face-back dimension, and the golf club head is divided into a face section that extends, in the face-back direction, from 0% of the face-back dimension to 25% of the face-back dimension, a middle section that extends, in the face-back direction, from 25% to 75% of the face-back dimension, and a back section that extends, in the face-back direction, from 75% to 100% of the face-back dimension, and wherein no more than 20% by weight of the middle section is made of a material having a middle section density of 4.0 g/cc and 20.0 g/cc;   the strike face has a balance point coefficient of restitution (COR) of at least 0.820-0.840 and a first center face CT is no more than 257 μs;   the strike face comprises a central region defined by a 40 millimeter (mm) by 20 mm rectangular area centered on the geometric center of the strike face, wherein the central region is elongated in a heel-to-toe direction;   the strike face comprises a first coefficient of restitution weighting factor and a first COR value positioned on the strike face at the geometric center of the strike face corresponding to an (x, y) coordinate of (0, 0);   the strike face comprises a second COR weighting factor and a second COR value positioned on the strike face 10 mm above the geometric center of the strike face corresponding to an (x, y) coordinate of (0, 10);   the strike face comprises a third COR weighting factor and a third COR value positioned on the strike face 10 mm below the geometric center of the strike face corresponding to an (x, y) coordinate of (0, −10);   the strike face comprises a fourth COR weighting factor and a fourth COR value positioned on the strike face 20 mm toe-ward of the geometric center of the strike face corresponding to an (x, y) coordinate of (−20, 0);   the strike face comprises a fifth COR weighting factor and a fifth COR value positioned on the strike face 20 mm heel-ward of the geometric center of the strike face corresponding to an (x, y) coordinate of (20, 0);   the first COR weighting factor is 0.3267, the second COR weighting factor is 0.2256, the third COR weighting factor is 0.1395, the fourth COR weighting factor is 0.2263, and the fifth COR weighting factor is 0.0819;   a summation of the first, second, third, fourth, and fifth COR weighting factors is 1;   the first COR value is no less than 0.817, the second COR value is no less than 0.801, the third COR value is no less than 0.775, the fourth COR value is no less than 0.785, and the fifth COR value is no less than 0.720; and   a weighted COR value is 0.804-0.820, the weighted COR value comprising a summation of:
 the first COR weighting factor multiplied by the first COR value, 
 the second COR weighting factor multiplied by the second COR value, 
 the third COR weighting factor multiplied by the third COR value, 
 the fourth COR weighting factor multiplied by the fourth COR value, and 
 the fifth COR weighting factor multiplied by the fifth COR value. 
   
     
     
         72 . A golf club head comprising:
 a body defining an interior region, the body comprising a sole portion, a crown portion, a skirt portion, a front portion comprising a strike face having a variable face thickness profile having a maximum face thickness that is at least 0.6 mm greater than a minimum face thickness, a heel opening configured to receive a fastening member, a head-shaft connection system including a sleeve that is secured by the fastening member in a locked position, the head-shaft connection system configured to allow the golf club head to be adjustably attachable to a golf club shaft in a plurality of different positions resulting in an adjustability range of different combinations of loft angle, face angle, or lie angle;   wherein:   a geometric center of the strike face defines an origin defining a coordinate system having multiple orthogonal axes, including an origin x-axis extending tangential to the strike face and parallel to a ground plane when the golf club head is at an address position, an origin y-axis extending perpendicular to the origin x-axis and parallel to the ground plane when the golf club head is at the address position, and an origin z-axis perpendicular to both the origin x-axis and the origin y-axis;   the golf club head has a center-face y-axis location (CFY) of 11-16 mm;   the golf club head has a face progression (FP) of 10-19 mm;   the body comprises a front body portion including a forward sole portion, a forward heel portion, and a forward toe portion, wherein the front body portion extends at least 20 mm rearward of the origin measured parallel to the origin y-axis   the golf club head has a volume of at least 300 cc, a body length of at least 103 mm, a moment of inertia about a CG x-axis (Ixx) of at least 280 kg·mm 2 , a moment of inertia about a CG y-axis (Iyy) is at least 275 kg·mm 2 , a moment of inertia about a CG z-axis (Izz) of at least 450 kg·mm 2 , a golf club head mass of 185-210 grams, and a center of gravity whose location is defined relative to the origin via a CGx coordinate, a CGy coordinate, and a CGz coordinate of less than −2.5 mm, the center of gravity location is at a Zup elevation, and a Delta1 distance of at least 15 mm;   at least a portion of the crown portion comprises one or more fiber reinforced polymer materials;   the golf club head has a rear mass element attached to the golf club head and having a rear mass element mass of at least 10 grams, wherein the rear mass element has a rear mass element y-axis coordinate of 90-120 mm;   the golf club head has a front mass element attached to the front body portion and having a front mass element mass that is different than the rear mass element mass, wherein the front mass element having a front mass element y-axis coordinate of no more than 30 mm;   the front mass element and the rear mass element are interchangeable, one of the front mass element mass and the rear mass element mass is 15-35 grams, one of the front mass element mass and the rear mass element mass is 10 grams or less, and each of the front mass element, the rear mass element, and the fastening member are configured to be engaged by a common tool;   the strike face has a balance point coefficient of restitution (COR) of at least 0.820-0.840 and a center face CT is no more than 257 μs;   the strike face comprises a central region defined by a 40 millimeter (mm) by 20 mm rectangular area centered on the geometric center of the strike face, wherein the central region is elongated in a heel-to-toe direction, and a first maximum characteristic time (CT) within the central region is less than 257 μs;   the strike face comprises a first coefficient of restitution weighting factor and a first COR value positioned on the strike face at the geometric center of the strike face corresponding to an (x, y) coordinate of (0, 0);   the strike face comprises a second COR weighting factor and a second COR value positioned on the strike face 10 mm above the geometric center of the strike face corresponding to an (x, y) coordinate of (0, 10);   the strike face comprises a third COR weighting factor and a third COR value positioned on the strike face 10 mm below the geometric center of the strike face corresponding to an (x, y) coordinate of (0, −10);   the strike face comprises a fourth COR weighting factor and a fourth COR value positioned on the strike face 20 mm toe-ward of the geometric center of the strike face corresponding to an (x, y) coordinate of (−20, 0);   the strike face comprises a fifth COR weighting factor and a fifth COR value positioned on the strike face 20 mm heel-ward of the geometric center of the strike face corresponding to an (x, y) coordinate of (20, 0);   the first COR weighting factor is 0.3267, the second COR weighting factor is 0.2256, the third COR weighting factor is 0.1395, the fourth COR weighting factor is 0.2263, and the fifth COR weighting factor is 0.0819;   a summation of the first, second, third, fourth, and fifth COR weighting factors is 1;   the first COR value is no less than 0.817, the second COR value is no less than 0.801, the third COR value is no less than 0.775, the fourth COR value is no less than 0.785, and the fifth COR value is no less than 0.720; and   a weighted COR value is 0.804-0.820, the weighted COR value comprising a summation of:
 the first COR weighting factor multiplied by the first COR value, 
 the second COR weighting factor multiplied by the second COR value, 
 the third COR weighting factor multiplied by the third COR value, 
 the fourth COR weighting factor multiplied by the fourth COR value, and 
 the fifth COR weighting factor multiplied by the fifth COR value.