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 leather or plastic, may have drop pockets, which are small nets, bags or cups to catch the balls. Ball returns, instead have a series of troughs or gutters inside the table, which channel the balls into a collection chamber on one side of the table. On a coin-operated table, the balls are deposited inside an inaccessible compartment window until the table is paid again, allowing the balls to be released into the collection chamber. A disadvantage to drop pockets is that if too many balls go into the same pocket, it will fill up the receptacle and prevent any more