Noel, IF maintenance is responsible for 15% (golfweek awhile back)
Then certainly other technological advances in training aids, dissemination of info, and starting younger, and staying fit, has to be worth 50%. That only leaves 35% percent to split between the the two I&B's.
Has anyone else seen how the dimple effects flight? The pbs documentary on the guy commisioned to blow-up dams in Germany during WWII illustrated the importance of the dimple.