Assertion: golf ball's cover | /r/HasProperty | stiff
Facets:
Source sentences:
text: The cover must be as stiff as possible to make the best possible use of the energy generated within and fly those long distances.
text: A Surlyn cover for a 3-piece construction needs to be lower modulus than the cover of the 2-piece construction to increase the ball spin but still be stiff enough to provide ball velocity.