Billiard table all six pockets), with rounded entrances and nearly parallel sides, like those on a snooker table. One tactical consequence of this design difference is that the jaws of the WPA-type pocket are often used exactly like a horizontal version of the backboard of a basketball goal, to rebound the ball into the pocket; this technique does not work on blackball tables, and even shots down the cushion into a corner pocket are more difficult. For tournament competition under WPA world-standardized rules (and league play under derived rulesets), the bed of the pocket billiard table must be made of slate no
Billiard ball juggling disciplines have often overlapped since their successful combination by pioneers like Paul Vandy. An urban legend received cultural attention to many saying, "If the Earth were the size of a billiard ball, it would be smoother". It was used in 2008's Discover Magazine, but mistook the diameter tolerance for smoothness. If the Earth were reduced to the size of a billiard ball, much of it, excluding the Himalayas and Mariana Trench, would be smoother. (see also: Earth's Shape) The phrase "as smooth as a billiard ball" is sometimes applied to describe a bald person, and the term "cue ball"