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 table In all cases, the table is rectangular with a ratio (e.g. ). There are only two sizes approved for tournament play by the International Olympic Committee-recognized sport governing body of pool, the World Pool-Billiard Association (WPA), and its various regional and national affiliates; under the world standardised rules of pool, these are the and models. For a table, the playing surface (the dimensions between the noses of the cushions) measures by with a (3.2 mm) margin of error for either dimension. For an , the playing surface measures by , with the same inch variance allowed. In the UK as