Abstract: A face insert for golf club head in one embodiment can comprise a substrate comprising a score line groove-free front surface. A cover layer is provided at least on the front surface of the substrate. The cover layer can alternatively overlay at least a portion of the peripheral edge of the substrate. The cover layer comprises a ball-striking surface spaced by the cover layer from the substrate. Plural elongated score line grooves can extend into the polymer layer from the ball-striking surface. In addition, visible markings are interposed between the cover layer and the front surface of the substrate, the visible markings being visible through the cover layer. In one form the visible markings comprise elongated score line markings and target markings in a central portion of the substrate. The visible markings can be screen-printed markings, which are then protected by the cover layer from wear. The cover layer can be molded and can be a polymer layer.

Abstract: The present disclosure provides a putter head that has a plurality of deflectable beams or projections for striking a golf ball. Upon impact with the ball, the beams deflect and rebound to impart topspin on the ball, thereby resulting in forward rotation of the ball shortly after impact. In certain embodiments, the striking surface of the putter is comprised of a plurality of generally parallel, vertically spaced, deflectable beams extending horizontally across a front surface of the putter. Each beam extends downwardly from a fixed end to a free end that can contact the ball. In one specific implementation, the beams can be formed directly in the front surface of the putter head. In another implementation, the beams are formed in an insert that is mounted to the front surface of the putter head.

Abstract: A golf club head having a multi-material face. The golf club head has a hard, wear resistant material as the ball-impacting face surface coupled to a softer material, allowing the multi-material face to be joined to a soft body material such that the body can be bent and customized. The multi-material face allows for improved playing characteristics by allowing the club designer to use a thinner face and lighter body material while still providing improved face wear resistance and durability.

Abstract: A putter-head (20) with a main body (22) having a striking face (24), a weight body (25) and an isolation layer 27 is disclosed herein. The striking face (24) has a dual milled pattern thereon. Preferably, a central area (40) has a first milled pattern and a periphery region (42) has a second milled pattern. The main body (22) is composed of a metal material, preferably a stainless steel material.

Abstract: A golf club head comprises a face portion whose front face forms a clubface having a clubface roll of a radius R, and the clubface is provided with a plurality of parallel grooves extending straight at an angle of not more than 10 degrees with respect to the toe-and-heel direction of the head so as to form at least one lateral zone between the parallel grooves, wherein the above-mentioned at least one lateral zone is provided with a convex curve of a radius (r) smaller than the radius R of the clubface roll.

Abstract: The present invention is directed to a golf club head with an improved striking surface. Grooves are machined into the strike surface with tight tolerances. The grooves have sharp edges, radiused ends, and a draft angle between about 2° and 12°. The striking face is machined such that it has a uniform texture with a roughness of more than 40 Ra. The grooves may contain a plurality of portions, including a radiused or angled portion, a portion having substantially parallel walls, a portion having a v-shape, and a curved portion. The grooves may also be characterized by various dimensions, including draft angle, inclusive side wall angle, width, depth, cross-sectional area, spacing, and pitch ratio. Preferred values for these dimensions are provided. A golf club head having a variety of groove types and a set of golf clubs with grooves varying among the individual clubs of the set are also disclosed.

Abstract: The present invention is directed to a golf club head with an improved striking surface. The grooves are machined into the strike surface with tight tolerances. The grooves have sharp edges, radiused ends, and a draft angle between about 2° and 12°. The striking face is machined such that it has a uniform texture with a roughness of more than 40 Ra. The face may be selectively textured to enhance certain shots that the golfer may perform. This may include providing a plurality of distinct sets of texturing to accommodate a plurality of different shots. The grooves may contain a plurality of portions, including a radiused or angled portion, a portion having substantially parallel walls, a portion having a v-shape, and a curved portion. The grooves may also be characterized by various dimensions, including draft angle, inclusive side wall angle, width, depth, cross-sectional area, spacing, and pitch ratio.

Abstract: The golf club is adapted for chip shots and has an upright shaft having a top grip and a bottom end; and a club head having (a) a hosel portion, (b) a trapezoidal clubface with a predetermined angle of loft, a longer leading edge and a relatively short trailing edge, (c) a sole plate having a similar profile to the clubface and defining a bounce angle with respect to a horizontal plane normal to the axis of the shaft, and (d) two opposite side walls in the shape of isosceles triangles for connecting the respective sets of opposing side edges of the clubface and sole plate with the apexes of the triangular side walls pointing away from each other. The leading edge of the clubface defines two acute angled points diverging forwardly of the club head to neutralize rough elements of sand, weed and other barriers and reach out to hit a nestled ball back to the fairway.

Abstract: A golf club head, according to one or more aspects of the present invention, comprises a metallic striking wall having a striking surface and at least one through score-line opening. At least one complementary component may be disposed rearward of the striking surface such that at least a part of the at least one complementary component extends into only a part of the at least one through score-line opening.

Abstract: An angled putting golf club head has a forward-angled face comprising a plurality of teeth constructed so as to impart to the ball a horizontal force with little or no vertical force at the point of impact, and to contact the ball above its center of gravity so that the ball has negligible sliding motion when first struck.

Abstract: The present invention is directed to a golf club head with an improved striking surface. The grooves are machined into the strike surface with tight tolerances. The grooves have sharp edges, radiused ends, and a draft angle between about 2° and 12°. The striking face is machined such that it has a uniform texture with a roughness of more than 40 Ra. The grooves may contain a plurality of portions, including a radiused or angled portion, a portion having substantially parallel walls, a portion having a v-shape, and a curved portion. The grooves may also be characterized by various dimensions, including draft angle, inclusive side wall angle, width, depth, cross-sectional area, spacing, and pitch ratio. Preferred values for these dimension are provided.

Abstract: This invention provides a plurality of grooves formed on a face of the golf club head. Each of a pair of side surfaces of each of the grooves has a first surface leading to the face and a second surface leading to the first surface in the depth direction of the groove. A first angle between the first surfaces of each of said pair of the side surfaces is larger than a second angle between the second surfaces of each of the said pair of the side surfaces. Edges of the groove are rounded. A width W (mm) of the groove measured including the rounded edges, a width Ws (mm) between the grooves adjacent one another, a width Wr (mm) of the groove measured based on the 30 degrees measurement rule and a cross section area S (mm2) of the groove satisfy the following expressions; W/Ws×100?40 (%), S/(Ws×0.5)×100?70 (%).

Abstract: A golf club head of this invention includes a face and a plurality of striations formed on the face by milling. A pitch P in the arrangement direction of the plurality of striations satisfies 300 ?m?P?600 ?m. The surface roughness of a region in the face with the striations satisfies in the maximum height of the profile Ry, 15 ?m?Ry?0.005×P+15.7 ?m.

Abstract: The present invention provides a golf club head comprising, a face, a plurality of score line grooves formed in the face, traces formed in the face by milling; and a pair of side surfaces of the score line groove including a first surface that is contiguous with the face and a second surface that is contiguous with the first surface in the depth direction of the score line groove. A first angle that is formed by each first surface of the pair of side surfaces is larger than a second angle that is formed by each second surface of the pair of surfaces. The face in which the traces are formed has the arithmetic mean deviation of the profile (Ra) of not less than 4.00 ?m.

Abstract: A putter head includes substantially parallel plural grooves formed on a face thereof, wherein a ratio W/S of a groove width W (mm) and a space width S (mm) between the grooves is from 0.5 to 2.0.

Abstract: A golf club head of this invention includes a face, a plurality of score line grooves formed on the face, and a plurality of striations formed on the face. The angle formed by an arrangement direction of the plurality of striations and the score line grooves is between 40 degrees and 70 degrees, inclusive, as viewed clockwise from a toe side end of the score line grooves.

Abstract: A putter head includes: a face; a first group of grooves which are mutually-parallel grooves; and a second group of grooves which differ in depth from the first group of grooves, wherein the face includes the first group of grooves and the second group of grooves.

Abstract: A golf club head of this invention includes a face, a plurality of score line grooves formed on the face, and traces formed in the face by milling. Edges of the score line grooves are rounded with a radius of not more than 0.2 mm. A width W (mm) of the score line groove measured with the rounded edge being included, a width Ws (mm) between the score line grooves adjacent to one another, a width Wr (mm) of the score line groove measured based on the 30 degrees measurement rule and a cross section area S (mm2) of the score line grooves satisfy the flowing expressions; W/Ws×100?35(%) and S/(Wr×0.5)×100?70(%). The face in which the traces are formed has the arithmetic mean deviation of the profile (Ra) of not less than 4.00 ?m.

Abstract: This invention provides a golf club head having a groove formed on a face of the golf club head. Each of a pair of side surfaces of the groove has a first surface leading to the face and a second surface leading to the first surface in the depth direction of the groove. A first angle between the first surfaces of each of the pair of the side surfaces is larger than a second angle between the second surfaces of each of the pair of the side surfaces.

Abstract: The invention is directed toward a trial golf club head and method for determining the optimal loft angle for any golf club, and in particular a hybrid-type golf club. The invention includes a trial golf club head having a face portion, a leading edge portion, a toe portion, a heel portion, a back portion having a trailing edge portion, and a sole portion. The sole portion contains a number of equally spaced graduated indicia, which are substantially parallel to one another and extend from the toe portion to the heel portion. The distance between the graduated indicia is approximately 3.75 centimeters (cm), which corresponds to an incremental loft angle of approximately 3 degrees. The sole portion has a radius of curvature of 71.67 mm, which extends from the leading edge of the face portion to the trailing edge of the back portion.

Abstract: This invention provides a golf club head having a plurality of grooves formed in a face thereof. Edges of the groove are rounded with a radius of not more than 0.2 mm. A width W (mm) of the groove measured with the rounded edge being included, a width Ws (mm) between the grooves adjacent to one another, a width Wr (mm) of the groove measured based on the 30 degrees measurement rule and a cross section area S (mm2) of the groove satisfy the following expressions; W/Ws×100?35(%), S/(Ws×0.5)×100?70(%).

Abstract: A golf club head having a toe portion, a heal portion and a club front intended striking face with a plurality of substantially parallel grooves formed in the face and extending horizontally between the toe portion and the heel portion. Each groove has a groove width such that the groove width increases from a center portion of the face towards the toe portion and the heel portion.

Abstract: The present disclosure provides a putter head that has a plurality of deflectable beams or projections for striking a golf ball. Upon impact with the ball, the beams deflect and rebound to impart topspin on the ball, thereby resulting in forward rotation of the ball shortly after impact. In certain embodiments, the striking surface of the putter is comprised of a plurality of generally parallel, vertically spaced, deflectable beams extending horizontally across a front surface of the putter. Each beam extends downwardly from a fixed end to a free end that can contact the ball. In one specific implementation, the beams can be formed directly in the front surface of the putter head. In another implementation, the beams are formed in an insert that is mounted to the front surface of the putter head.

Abstract: The invention includes a golf club iron head, correlated sets of individually numbered golf club irons, methods of matching a golf club to a golfer, and methods of matching a set of golf clubs to a golfer. In one implementation, a golf club iron head includes a front striking face, a sole, a toe, and a heel. The front striking face has a series of grooves of a common cross sectional shape from the top to the bottom. Individual grooves have a base and opposing sidewalls which diverge from the base and extend outwardly in the direction of the front striking face. The sidewalls include opposing protrusions extending into the groove proximate the front striking face. In one implementation, the front striking face of a golf club iron head defines a symmetrical groove cross section. The groove base comprises a protrusion extending in the direction of the front striking face. The base protrusion has an apex received inwardly of the front striking face.

Abstract: The present invention is directed to a golf club head with an improved striking surface. The grooves are machined into the strike surface with tight tolerances. The grooves have sharp edges, radiused ends, and a draft angle between about 2° and 12°. The striking face is machined such that it has a uniform texture with a roughness of more than 40 Ra.

Abstract: The high spin golf club uses modified grooves for use on all types of known golf clubs, wherein the modified grooves maximizes control of the golf ball through increasing backspin. The high spin golf club's modified grooves can be used alone or in a combination with conventional grooves to tailor the properties of the club face. The modified grooves are of varied configurations and all modified grooves can be used in combination with any other modified or conventional grooves to maximize the backspin of the golf ball and tailor the spin properties of the face of the club. Further a method for making high backspin golf clubs that reduce cover damage of golf balls is disclosed.

Abstract: A set of iron-type golf clubs includes long irons with channel back configurations and short irons with cavity back configurations. The rear face configurations transition from channel backs through to pure cavity backs for increased performance continuum for the set. Additional design parameters for the set may also be systematically varied through the set, such as groove type and depth, loft angle, cavity volume, hitting face roughness, and sole width. At least one of the clubs of the set includes a sandwich-type construction for the hitting face having a dampening element disposed between a hitting face insert and a lightweight reinforcing core. In one embodiment, at least one club head is oversized.

Abstract: A putter-head (20) with a body (22) having a striking face (24) is disclosed herein. The striking face (24) has a dual milled pattern thereon. Preferably, a central area (40) has a first milled pattern and a periphery region (42) has a second milled pattern. The body (22) is composed of a metal material, preferably a stainless steel material.

Abstract: A golf club head striking face is provided, including a plurality of grooves, wherein at least one groove has a first and second side. Each side includes a bottom, a lower section, and an upper section. The lower section is substantially planar and disposed between the bottom and the striking face. The upper section is substantially planar and disposed between the lower section and the striking face. A first draft angle is measured between the upper sections of the first and second sides, and a second draft angle is measured between the lower sections and the first and second sides, wherein the first draft angle is greater than the second draft angle. In addition, the distance between the first and second sides continuously increases from the bottom to the striking face.

Abstract: A new Golf Club Head design, as compared to the previous art, Cylindrical in shape, with a larger more concentrated Circular face that has Circular Grooves, with a Convex back, with no Heel and Toe, has a sole plate that wraps around the convex back up to the half mark on both sides of the wooden golf club head, and a unique Neck, Hosel Tube Neck and Shaft ‘placement’ that abuts the approximate Center on the outside at right angles to the golf club head. And this new design incorporates a multifaceted hand grip for the club shaft. This Cylindrical shape head will permit the club head to be always soled and as such, the golf club will not fall backwards as the prior art does without the shaft being held firmly by the golfer. And, so, with this new multifaceted hand grip design, the golfer would not have to hold onto the club shaft any tighter in order to prevent the golf club from twisting, in his/her hands, at impact with the golf ball.

Abstract: A golf club head comprises a face portion having a front face defining a clubface for hitting a ball and a back face facing a hollow, wherein the clubface is provided along the edge thereof with a frontal groove having a groove width of not less than 0.5 mm, and the back face is provided with a backside groove extending along the frontal groove.

Abstract: A method and apparatus providing a golf club head configured to minimize sliced golf shots. The golf club head includes a club head body having an external surface with a toe portion, a heel portion and a sole portion, the heel portion having a hosel extending therefrom. The club head body also includes a ball striking face disposed between the toe portion and the heel portion, which defines a horizontal center line and a vertical center line located symmetrically on the ball striking face. The ball striking face includes a bulge radius and a roll radius merging to an apex defined to be along an apex angle ranging from approximately 54° to 80° from the vertical center line toward the toe portion and below the horizontal center line. With this arrangement, the position of the apex is configured to minimize sliced golf shots.

Abstract: A set of golf club wedges each having a club face (10) is disclosed wherein the lofts of the individual clubs progressively increases. The hitting surface of each club head may take the form of an insert (12) that includes a series of grooves, the design of which is varied from club to club to provide increasing friction with loft. As a result, a golfer can impart the same amount of spin to a golf ball with each of the wedges despite a substantial difference in loft and club head swing speed between the respective clubs. In addition, the surface roughness of the hitting surface may also be increased as loft increases to further control the spin imparted to the ball.

Abstract: The high spin golf club uses modified grooves for use on all types of known golf clubs, wherein the modified grooves maximizes control of the golf ball through increasing backspin. The high spin golf club's modified grooves can be used alone or in a combination with conventional grooves to tailor the properties of the club face. The modified grooves are of varied configurations and all modified grooves can be used in combination with any other modified or conventional grooves to maximize the backspin of the golf ball and tailor the spin properties of the face of the club. Further a method for making high backspin golf clubs that reduce cover damage of golf balls is disclosed.

Abstract: A golf-putter head (1) has a grooved impact face (5) defining lengthwise ridges (7) for impacting a dimpled golf-ball in areas of contact that are distributed around the dimples for improvement of putt accuracy by collectively centralizing the resultant striking force on the ball. The profile, width w and pitch p of the ridges (7) are selected according to hardness h and with p and w not exceeding 3.5 mm and (p?0.4) mm respectively, to reduce the standard deviation of dimple-effect error distribution by at least 15% in putting with initial ball-velocity of 2.5 m/s. Ridge-profile is symmetrically rounded (FIGS. 2,4,5,21), flat (FIG. 6,20) or segmented-flat (FIG. 3), or asymmetrical (FIG. 19), and test apparatus (FIGS. 11, 12) uses a linear actuator (33) for projecting the ball repeatedly to drop onto an impact-recording plate (36) to reveal scatter due to dimple-effect error.

Abstract: A golf club head is provided, including a planar face with a pattern of horizontal grooves therein each having a cross section with an opening in the planar face. The grooves each include a first side, a second side, a pair of top junctures where the first and second sides join the planar face, a bottom and a pair of bottom junctures where the first and second sides join the bottom. The spacing between the first and second sides continually increases from the bottom to the top junctures. Each of the sides includes a lower section positioned nearer the bottom and an upper section positioned nearer the face. Each of the lower and upper sections is substantially planar. The top junctures are convexly rounded and the bottom junctures are concavely rounded.

Abstract: An improved face for a golf club head includes shallow and deep markings configured to provide a pleasing appearance when viewed head on, and to frame the central region of the impact surface of the face when viewed at address. Use of only shallow markings in the central region of the impact surface prevents existence of stress fractures resulting from use of deep markings in the central region. This allows for a face thinner than those incorporating conventional grooves in the central regions of their impact surfaces, resulting in both superior resistance to cracking and improved C.O.R. Specified methods of manufacture are particularly suited for making clubs incorporating these shallow and deep markings.

Abstract: The invention includes a golf club iron head, correlated sets of individually numbered golf club irons, methods of matching a golf club to a golfer, and methods of matching a set of golf clubs to a golfer. In one implementation, a golf club iron head includes a front striking face, a sole, a toe, and a heel. The front striking face has a series of grooves of a common cross sectional shape from the top to the bottom. Individual grooves have a base and opposing sidewalls which diverge from the base and extend outwardly in the direction of the front striking face. The sidewalls include opposing protrusions extending into the groove proximate the front striking face. In one implementation, the front striking face of a golf club iron head defines a symmetrical groove cross section. The groove base comprises a protrusion extending in the direction of the front striking face. The base protrusion has an apex received inwardly of the front striking face.

Abstract: In a putter, at least one adjustable weight is provided which can be moved to different positions longitudinally along the putter head. The putter head is provided with a open channel with closed ends. The weight is slidably mounted within said outer chamber with bolts extending through a slot into a slide within the channel, and the bolt is adapted to be screw tightened into said slide to hold said weight in position. A vibration damping plate is disposed between the weight and the putter head. The front face of the putter is provided parallel vertical grooves defined in the front face, and the grooves are separated by flat lands between The grooves are arcuate in cross section so that the sidewalls of the groove slope is at an angle substantially less that perpendicular to the lands.

Abstract: The invention includes a golf club iron head, correlated sets of individually numbered golf club irons, methods of matching a golf club to a golfer, and methods of matching a set of golf clubs to a golfer. In one implementation, a golf club iron head includes a front striking face, a sole, a toe, and a heel. The front striking face has a series of grooves of a common cross sectional shape from the top to the bottom. Individual grooves have a base and opposing sidewalls which diverge from the base and extend outwardly in the direction of the front striking face. The sidewalls include opposing protrusions extending into the groove proximate the front striking face. In one implementation, the front striking face of a golf club iron head defines a symmetrical groove cross section. The groove base comprises a protrusion extending in the direction of the front striking face. The base protrusion has an apex received inwardly of the front striking face.

Abstract: A method of manufacturing a face plate for a golf club head is presented to provide face having substantial thickness variation for enhanced performance. The method includes the steps of providing a rolled sheet of metal material having an initial thickness and forming a blank having a prescribed outer shape from the material. The method also includes machining a second side of the blank such that the resulting face plate has a variable thickness. The machining is such that the plate has a first thickness less than or equal to the initial thickness, a second thickness less than the first thickness and a third thickness less than the second thickness. The machining is performed over a substantial portion of the surface area of the second side. Either a CNC lathe or milling machine may be used; however, for an axisymmetric face thickness a CNC lathe is preferred and for an asymmetric face thickness a CNC end mill is preferred. The club head may be a wood-type or iron, and titanium or steel alloys may be used.

Abstract: An improved face for a golf club head includes shallow and deep markings configured to provide a pleasing appearance when viewed head on, and to frame the central region of the impact surface of the face when viewed at address. Use of only shallow markings in the central region of the impact surface prevents existence of stress fractures resulting from use of deep markings in the central region. This allows for a face thinner than those incorporating conventional grooves in the central regions of their impact surfaces, resulting in both superior resistance to cracking and improved C.O.R. Specified methods of manufacture are particularly suited for making clubs incorporating these shallow and deep markings.

Abstract: The invention relates to a golf club (1) comprising a shaft (3) provided with a handle portion (2) and a club blade (5) projecting from the lower portion (4) of said shaft (3), the hitting surface (6) of said blade is provided with a plurality of scores or grooves (7). Those grooves (7) are arranged at a predetermined mutual distance and do extend in a diverging or parallel pattern or area over at least the hitting surface (6) of the club blade (5).

Abstract: A golf club head (20) having a thin striking plate (30) with a smooth exterior surface and a thin layer (35) disposed on the exterior surface (53). The thin layer (35) has a plurality of scorelines (75) that absorb the shock during impact with a golf ball. The striking plate (30) has a thickness in the range of 0.010 inch to 0.200 inch, and the thin layer (35) has a thickness in the range of 0.003 inch to 0.050 inch. The striking plate (30) may have a uniform thickness or a variable thickness.

Abstract: A golf club head comprises a main body that defines a front face. The front face includes a plurality of projections extending from the front face. The ends of the projections define a plurality of individual contact surfaces for striking a golf ball. The plurality of projections prevent a golf ball from contacting the front face thereby resulting in a change of the golf ball general contact area. A golf club incorporating the club head provides improved control of a golf ball and also provides improved feel when the club head impacts a golf ball.

Abstract: A golf club for effecting shots within sixty yards of play to the “green”. The golf club includes two distinct shaft configurations and has a club head with a striking face or impact surface which gradually narrows downwardly to a rounded bottom edge to form a convex shaped structure having a series of cavity contours for effecting different degrees of impact with a target. The convex top surface of the golf club head has a series of seven colored parallel grooves incorporated thereon to form an optical pattern to help a golfer's eyes focus and to project a more broad-based target line-up. The angle between the line-up defined by the shaft when positioned normally as during play and a line perpendicular to the ground is six to seven degrees.

Abstract: A golf club head having a striking plate with variable roll radius of curvature and a variable bulge radius of curvature is disclosed herein. The striking plate preferably has a large surface area which requires correction of off-center shots. The striking plate may be used on a fairway wood-type golf club head or a driver-type golf club head. The striking plate is preferably composed of steel or titanium.

Abstract: A golf club head comprises a main body that defines a front face. The front face includes a plurality of projections extending from the front face. The ends of the projections define a plurality of individual contact surfaces for striking a golf ball. The plurality of projections prevent a golf ball from contacting the front face thereby resulting in a change of the golf ball general contact area. A golf club incorporating the club head provides improved control of a golf ball and also provides improved feel when the club head impacts a golf ball.

Abstract: An improved face for a golf club head includes shallow and deep markings configured to provide a pleasing appearance when viewed head on, and to frame the central region of the impact surface of the face when viewed at address. Use of only shallow markings in the central region of the impact surface prevents existence of stress fractures resulting from use of deep markings in the central region. This allows for a face thinner than those incorporating conventional grooves in the central regions of their impact surfaces, resulting in both superior resistance to cracking and improved C.O.R. Specified methods of manufacture are particularly suited for making clubs incorporating these shallow and deep markings.

Abstract: A golf putter including a head attached rigidly to a shaft through the center of mass to minimize lateral rotation and to promote a pendulum like stroke, having optimized mass and shape to create a powerful “sweet spot” enabling consistent distance control, superior “feel” and increased “touch” while providing tangible “forgiveness” for random changes in dynamics introduced by less skilled players; the head having a continuous face comprised of a non-radial contour to provide improved rebound trajectory by initiating overspin and minimizing outside effects on the ball until all gyroscopic properties allow it to become a stabilized mass. The head includes a narrow sole to decrease drag, a doze to brush back taller grass, increasing the odds of making putts launched from less manicured greens or fringe areas, and semi circular markings approximating the radius of a golf ball to enable alignment of the ball with the “sweet spot”.