A method for measuring the swing time of a golfer's swing and selecting a golf club having k divided by four times the club's natural frequency (f.sub.n) approximately equal to the golfer's swing time. The golfer's swing time is defined as the time elapsed between maximum deflection of a club shaft during downswing until ball impact. The adjustment factor, k is in the equation since the motion of a golf swing is not periodic motion. The adjustment factor, k is determined by measuring the swing time of a representative golfer, finding the preferred f.sub.n for his swing and solving the above equation for k. In the preferred embodiment, an accelerometer is mounted within the club head and is connected to an electronic data processor. A graph of club head angular or radial acceleration versus time is plotted and the swing time is measured from the graph, between either peak angular acceleration or the latest point of maximum slope for radial acceleration and ball impact.