Provided is an impact point estimation apparatus that is capable of estimating, easily and with high accuracy, an impact point on a face surface of a golf club head at the time of a golf swing. The impact point estimation apparatus includes an acquisition part configured to acquire time-series sensor data that is output from at least one of an angular velocity sensor and an acceleration sensor attached to at least one of a grip and a shaft of a golf club and an estimation part configured to estimate the impact point, according to a shaft characteristic which is a characteristic of the shaft, based on the sensor data.

Device and method for determining and comparing distances between balls in the game of bocce in which a marker block is magnetically attached to a measuring tape in a position corresponding to the distance between a first thrown ball and a target ball, and the tape with the marker attached is then used to compare that distance with the distance between a second thrown ball and the target ball to determine which of the two thrown balls is closer to the target ball.

An iron-type golf club having selectively machined portions and attributes.

Provided is a weight pattern determination apparatus for determining, in a golf club having a head capable of mounting one or more weights in a plurality of mounting patterns, the mounting pattern suited to a golfer. The apparatus has an impact point specification unit and a pattern determination unit. The impact point specification unit specifies an impact point distribution of the golfer. The pattern determination unit determines a recommended pattern which is the mounting pattern that approximates a sweet area of the golf club to the impact point distribution. According to the first aspect of the present invention, the impact point distribution of the golfer is specified, and a mounting pattern is determined based on this impact point distribution.

A golf club includes a club head having a volume of greater than about 360 cm.sup.3 and a mass less than 200 g. A shaft attachable to the club head has a tip end, a butt end, and a shaft balance point distance, BP.sub.s, as measured from the butt end, of no more than 19 inches. And the golf club has a mass less than 300 g.

A laser mandrel system that self-centers within a hosel bore of a golf club head to allow for precision adjustment of lie and loft is disclosed herein. The mandrel includes a one-piece housing with upper and lower portions, a laser centered within the upper portion of the housing, and a plurality of o-rings extending around an exterior or interior surface of a lower portion of the housing.

A device and method for identifying a center of a striking face of a golf club head are disclosed. The center determining device includes a device body having a central opening defined through a first surface of said device body and a second surface opposite said first surface. A first dimension indicator including a pair of first indicator jaws and a second dimension indicator including a pair of second indicator jaws may be disposed on said device body. A first adjuster and a second adjuster are operable to adjust said first separation distance said pair of first indicator jaws and a second separation distance between said second indicator jaws. When the pair of first indicator jaws and the pair of second indicator jaws are equally spaced around the heel, toe, topline, and sole edges of the striking face, the central opening is aligned with the center of the striking face.

A golf club includes a club head having a volume of greater than about 360 cm.sup.3 and a mass less than 200 g. A shaft attachable to the club head has a tip end, a butt end, and a shaft balance point distance, BP.sub.s, as measured from the butt end, of no more than 19 inches. And the golf club has a mass less than 300 g.

A device and method for identifying a center of a striking face of a golf club head are disclosed. The center determining device includes a device body having a central opening defined through a first surface of said device body and a second surface opposite said first surface. A first dimension indicator including a pair of first indicator jaws and a second dimension indicator including a pair of second indicator jaws may be disposed on said device body. A first adjuster and a second adjuster are operable to adjust said first separation distance said pair of first indicator jaws and a second separation distance between said second indicator jaws. When the pair of first indicator jaws and the pair of second indicator jaws are equally spaced around the heel, toe, topline, and sole edges of the striking face, the central opening is aligned with the center of the striking face.

An iron-type golf club and a method of creating the iron-type golf club including the steps of forming a club head blank having an external sacrificial region with an ESR thickness, an ESR sole portion, an ESR face portion, and an ESR leading edge portion. A finished club head is formed having a finished club head weight of less than 310 grams by machining off an ESR removed mass from at least a portion of the external sacrificial region including at least a portion of the ESR sole portion, a portion of the ESR face portion, and a portion of the ESR leading edge portion.