Many of the misconceptions about pool rules arise from the different sets of rules used by the UK's largest pool associations, the British Association of Pool Table Operators (BAPTO) and the English Pool Association (EPA). The former, which organises many competitions and leagues, uses the rules of the Europe and United Kingdom Pool Federation, often known as BAPTO rules. The EPA switched to the rules of the World Eight-Ball Pool Federation, commonly known as "World" rules, in 1998. However, the situation is further confused by some leagues using the "old" EPA rules.
Breaking OffIn World rules, the break shot is fair if four object balls hit a cushion or an object ball is potted. In BAPTO rules, two balls must come back past the middle pockets, or a ball must be potted. In both sets of rules, a foul break results in the balls being re-racked, with the opponent awarded two shots (see below). Similarly, if the black is potted from the break, the balls are re-racked and the same player breaks again, with no penalty.
Foul Strokes
In World rules, a foul results in an opponent being awarded 2 shots and being allowed to play the cue ball from any point behind the baulk line. The 2 shots "carry over," so if a player pots a ball with his or her first stroke, they still have 2 shots remaining. BAPTO rules, in addition to an extra visit, allow a player to place the cue ball in the "D" and legally play any ball. However, the extra visit does not "carry over," so a ball potted on the first visit leaves just one remaining.
Choice of Colours
In World rules, a ball or balls potted from the break allow a player to nominate either colour. However, a ball of that colour must be potted in order for the player to be "on" that colour. If no balls are potted from the break, the table remains "open" until a ball is fairly potted, the player then being "on" that colour. In BAPTO rules, after a fair break, the player nominates his or her colour, regardless as to the balls potted and is then "on" that colour.
Definition of a Legal Shot
BAPTO rules decree that the cue ball must merely strike a ball "on." This is also the case in World rules, although a ball must also strike a cushion or be legally potted. The exception is when snookered, in which case a legal shot is for a player to merely strike a ball "on."
Deliberate Fouls
In World rules, deliberate foul strokes are allowed and players often use such a stroke to clear a pocket obstructed by an opponent's ball. However, in BAPTO rules, deliberately playing an opponent's ball means immediate loss of frame.
Shooting Backwards
There is also variation in the handling of "shooting backwards" (behind the baulk line, after the cue ball is respotted after being potted. Possibilities here include: a player may not hit a ball that is on or behind the baulk line without first hitting another ball or cushion; may not shoot backwards from the baulk line, but may shoot at balls behind the line provided that the direction of motion of the cue ball is forward; or may simply be allowed to shoot backwards.