[Yoda]

My post was a general statement concerning the Ball's 'bounciness'. Measured by the Coefficient of Restitution (C.O.R.), this bounce enables the Ball to leave the Clubface at a speed faster than that of the Clubhead. This Coefficient is about 0.7 with the modern 'high compression' Ball, which means that Ball Speed will be approximately 40 percent greater than Clubhead Speed.

My example of dropping a Ball from shoulder height onto concrete was meant only as a simple appeal to the reader's common sense, not to indicate how the C.O.R. is determined in the laboratory or how Ball velocity is tested by Rules Officials. For example, by dropping a Ball from a known height (H) and measuriing its bounce (B), we can determine the C.O.R. as follows:

H/B = Coefficient Squared

Assuming a Ball is dropped 36 inches and bounces 22 inches, the 'bounce Ratio' (H/B) would be 0.61. Since this number is the Coefficient Squared, the Coefficient would be its square root, or 0.78. However, because this test (the drop from the shoulder) was at low speed, the result somewhat overstates the actual coefficient (which we've seen is about 0.7.). This is the rationale behind the Rule stating that the Ball's velocity must be measured on an R&A device that approximates a driver's Impact.

When a Ball is struck under circumstances approximating actual playing conditions, it is deformed ('flattened' on the Clubface) far greater than when simply dropped. This flattening of the Ball and subsequent rebound causes a loss of energy, and the greater the flattening, the greater the loss and the lower the Ball Speed. Because the 'harder' (higher compression) Ball flattens less than the low compression alternative, it leaves the Clubface at a higher Speed.

Certainly, other factors will affect the Ball's ultimate performance and suitability for a given player's Game , e.g., basic structure, dimple design, materials, weight, durability and manufacturing quality controls. But for the reasons stated, the high compression Ball will generally perform better than the low compression Ball (at any clubhead speed).