Assertion: bowling ball's surface | /r/HasProperty | bumpy
Facets:
Source sentences:
text: The surface of a proactive coverstock is bumpy, and it allows the ball to dig into the surface of the lane, creating the highest friction available on lanes that are heavily oiled.
text: Particle bowling balls (and by nature, composite cover stock bowling balls) are built for heavy-oil lanes, with surfaces that are textured and bumpy in order to create maximum friction.