A golf club head is provided having a club body having a front portion, a rear portion, a toe portion, and a heel portion. The club head also having a central portion connected with the front portion. A frame is connected with the central portion configured to provide a lightweight crown portion being located above an offset plane.

A golf putter is provided having a center core which extends through the putter head, the shaft, and into the grip. The center core not only acts as the backbone of the putter, the center core extends to the outer edges of putter and thus determines the shape of the putter. Additional parts necessary for a complete putter such as the putter head, shaft, and grip are attached to the center core to form a functional putter.

A golf club training device including: a body having a first end configured to be gripped by a user and a second end longitudinally extended from the first end; and a swing speed sensor disposed at the second end for producing an output signal for determining a portion of a golf swing having a greatest swing speed. A golf club training system is also provided to include: a plurality of the golf club training devices wherein at least two of each of the plurality of golf club training devices having one or more of a different weight and length.

A putting training device attachment including a shaft mount for mounting on a putter shaft; a pendulum assembly mounted on the mount; an indicating gauge connected to the pendulum assembly for indicating a preferred track for the pendulum. A putter is described for training.

A golf club fitting apparatus and a method for fitting using the apparatus are provided. The golf club fitting apparatus may be attached to a golf club and provide fitting information including effective lie angle, effective loft angle, stroke plane, and aiming verification information. That golf club fitting apparatus includes a first opening for receiving a shaft, second openings for receiving a collimated light source, third openings for receiving angle indicators, and a recess for securing the collimated light source in an alternate configuration.

A method for analyzing sensor data from baseball swings (or swings in similar sports) that transforms data into a reference frame defined by the bat orientation and velocity at impact. The trajectory of the sweet spot of the bat is tracked through the swing, and is analyzed to generate metrics describing the swing. A two-lever model of the swing may be used to model the effects of body rotation and wrist rotation. Data may be analyzed to identify relevant events during the swing such as start of downswing, commit (wrist release), on-plane, peak bat speed, and impact. Illustrative swing metrics derived from the sweet spot trajectory, the swing plane reference frame, and the two-lever model include: forward bat speed, on-plane rotation, hinge angle at commit, hinge angle at impact, body rotation ratio, body tilt angle, and swing plane tilt angle.

A golf club head has a body defining a ball striking face. The body further has a first leg extending away from the ball striking face and a second leg extending away from the ball striking face wherein a void is defined between the first leg and the second leg. The body further defines a cover that extends over the void. The golf club head may further have support structures and adjustable weight members.

Disclosed herein is an electronic device holder comprising a body having a back portion, a first body end, a second body end, and a first and second side portion. The device holder further comprises a clamp on the back portion of the body that is configured to removably attach and secure the body of the electronic device holder to a golf club shaft. The clamp comprises a first and second arm portion each comprising a support portion, an arcuate portion, and a guide portion. The guide portions assist in aligning and inserting the electronic device holder onto the golf club shaft. Furthermore the first body end, the first side portion, and the second side portions of the holder body comprise curved portions that assist in securing the electronic device into the holder. Other embodiments and systems are described herein.

The invention is a device attachable to a golf club which provides feedback, when the ball is struck on a sub-optimal area of the clubface, or at a suboptimal angle. The device is shaped to cover certain areas of the clubface, except the desired striking zone, such that the golf ball strikes the device during an impact resulting from a golf swing with sub-optimal swing path, attack angle or club face angle. The device provides physical and audible feedback, during impact of a golf swing, due to the differing feel and sound generated when the ball impacts the device, rather than the optimal area of the clubface. The device provides visual feedback, as due to the convex shape of the device, a differing golf ball flight is achieved when the golf ball impacts the device rather than the optimal area of the clubface.

A method for analyzing sensor data from baseball swings (or swings in similar sports) that transforms data into a reference frame defined by the bat orientation and velocity at impact. The trajectory of the sweet spot of the bat is tracked through the swing, and is analyzed to generate metrics describing the swing. A two-lever model of the swing may be used to model the effects of body rotation and wrist rotation. Data may be analyzed to identify relevant events during the swing such as start of downswing, commit (wrist release), on-plane, peak bat speed, and impact. Illustrative swing metrics derived from the sweet spot trajectory, the swing plane reference frame, and the two-lever model include: forward bat speed, on-plane rotation, hinge angle at commit, hinge angle at impact, body rotation ratio, body tilt angle, and swing plane tilt angle.