Diamonds on a pool table mean?

The billiard table diamonds, which are often dots rather than diamonds, are placed on the rails to divide the table. The foot string, head string, and table center are found by using the diamonds. In addition, they can be used to determine bank shot calculations. Their distance from playing surface points allow them to be used for more accurate aim and calculations for difficult shots. There are more than 100 published "diamond systems" to calculate bank shots using the diamonds.