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 increase difficulty. The amount of (trimmed underside of the rubber cushion's protruding at the pocket opening), if any, has a strong effect on how easily a ball is accepted by the pocket (the ""). On snooker and English billiards tables, the pocket entries are rounded, while pool tables have sharp "". This affects how accurate shots need to be to get into a pocket, and how fast they can be when not dead-on, including shots that run along and against a cushion, making snooker more difficult to play than pool. According to the WPBSA official rule book, "the pocket openings