Technical Time Out!
Relative to lesser of the oblique impacts, driver, fairway, hybrid:
1. Translating up the face, (sliding) will increase spin. The affect is linear in terms of compressive loading.
2. The greater the distance the ball slides prior to the point of separation, the greater it will spin.
3. Luberous coatings, lower the coefficient of friction! The lower the coefficient of friction, the less distance the ball will travel (compressively load) up the face. The rounder the ball will remain, the less it will spin. The greater energy it has to project = higher ball speed lower spin.
4. COR is a measurement of loss. Contrary to marketing, the "spring-like" affect is in fact, face compliance in the normal direction. IT IS NOT possible for a passive unsupported face (as found in all USGA compliant drivers) to rebound in time, during the secong half of the impact event, so as to trampoline the ball outbound. We do however tailor face compliance, to minimizing ball travel, reducing the quantity of deformation in the ball (compression / flattening) over the impact event. This will achieve a rounder golf ball, higher outbound ball speed at the point of separation. The higher the COR in a driver or HOT fairway metal, the greater the face deflection. The more the face complies, the less the ball will flatten.
5. Conversely, with oblique impacts, say wedges, whereby high spin is the desired affect. We tailor clubheads around material hardness. The harder the face (head) material, the greater the affective force load of impact, regardless of swing speed. The Harder the face, the more the ball will compressively load in the face normal direction, the less the ball will travel up the face, the greater it will spin. In conjunction with faces having inherently higher coefficient of friction and face and groove spec (latter within USGA' defined guidelines) work to channel moisture, affectively creating "rolling friction".