Blonde Girl Playing At The Billiard Table

Sights, or diamonds, are put on the rails to aid in the aiming of bank or kick shots. There are six along each long rail (with the side pocket interfering with where the seventh one would go) and three along each short rail. These divide the playing surface into equal squares.
Spots are often used to mark the head and foot spots. Other markings may be a line drawn across the head string and the outline of the rack behind the foot spot where the balls are racked. In addition, in artistic pool, lines are drawn between opposite sights putting a grid on the playing surface.