ballspeed to ct relationship is negatively affected normalized ball speed removes the variable effect of a golf club head 39 s mass and loft and the construction of a particular golf ball from testing the speed of a golf ball upon impact with any given golf club head including the golf club head 10 of the present invention in other words it allows an apples to apples comparison of golf club head performance normalized ball speed can be determined for a golf club head using the following steps which are also outlined in the flow chart of fig1 first provide a titanium 6 4 calibration plate 90 with a mass of approximately 190 grams a diameter d 4 of approximately 4 inches a minimum plate thickness pt 1 of approximately 0 100 0 150 inch and a maximum plate thickness pt 2 of approximately 0 200 0 400 inch as shown in fig1 and 13 and strike the center 92 of the calibration plate with a test golf ball moving at approximately 109 mph step 200 measure the return velocity v br of the ball step 210 then strike the same test golf ball again traveling at approximately 109 mph with the center 105 of the striking face section 100 of the golf club head 10 being assessed step 220 and measure the rebound velocity v cr of the.