Each shot in an artistic billiards match is played from a well-defined starting position. In fact, in some tournaments the balls must be placed within two millimeters of a diagrammed position. Each shot must also be done in an established manner in order for points to be awarded. Players are allowed three attempts at each shot. In general, the 76 shots in the game—even the lowest difficulty 4-point shots—require a high degree of skill, much practice and specialized knowledge to perform.