[Seat Ninja]

It's not anything to do with bowling balls. Or balls of any sort for that matter. Balls in any form only occur in a game every other year (don't believe me? Look it up i'm right). ex: 2008's track balls, 2006's nerf balls, 2004's kickballs, 2002's soccer balls, 2000's plastic balls, 1998's rubber balls, 1996's rubber balls, 1994's soccer balls, 1992's tennis balls, and i couldn't find 1990's game. But i don't know i may be wrong.