What shape are ball bearings? They are shaped like a ball, as everyone knows, right?

The funny thing about what everyone knows is that everyone can be wrong. For instance, everybody thinks that the America's Cup is an ocean-sailing race, and yet the Swiss managed to win the Cup. For those readers who are geographically-challenged, Switzerland is a land-locked country comprised entirely of mountains.

What does this have to do with ball bearings. Very little, I suspect, but balls have very little to do with ball bearings, either. Ball bearings look more like hula hoops. But don't try using them for that