8 ball pool is played with fifteen numbered object balls and the cue ball. The shooter’s group of seven balls (one through seven or nine through fifteen) must all be off the table before he attempts to pocket the eight ball to win. Shots are called.
Before groups are determined, the table is said to be “open,” and before each shot, the shooter must call his intended ball. If the shooter legally pockets his called ball, the corresponding group becomes his, and his opponent is assigned the other group. If he fails to legally pocket his called ball, the table remains open and play passes to the other player. When the table is “open”, any object ball may be struck first except the eight ball
The shooter remains at the table as long as he continues to legally pocket called balls, or he wins the rack by pocketing the eight ball.