The Balls should have a diameter of 21/16”. All balls should be of equally weighted. There are 3 balls in Billiards. Red termed as Object Ball, One White, and One Yellow Ball. are used as cue balls for both the players. Mean to say, if the first player has white as a cue ball, the yellow ball remains as another object ball during the first player's turn and in the second player turn, the position is exactly opposite, the yellow becomes cue ball, and white considered as another object ball.