The majority of American billiard tables have them, most professional players swear by them and beginners wonder what their purpose is. The Diamond System is used on American pool tables to improve accuracy and overall performance in a game of billiards. And with a simple bit of practice (and a touch of geometry!), it can be used by you too. The following guide applies to 9 foot tables.
Take a look at an American billiards table. On nearly every table you’ll notice little marks inlaid into the frame of the rails, often a table manufacturer will use diamonds as the markers It is these diamonds which can assist you in choosing the proper angles for kick shots and banks and ultimately act as your aiming system. The diamonds form invisible lines on a table, which go from diamond to diamond; from left to right. The general principle is if you hit the cue ball perfectly straight at one diamond, it will travel completely straight back towards the diamonds at the opposite end of the table and when used properly, you can calculate or visualise the precise impact point to send the cue ball (or object ball) to any other spot on the pool table. So if you hit from ten degrees, either way, it should rebound ten degrees out in the opposite direction. Simple! However, if you find yourself playing a situation where a diamond isn’t in the right spot, this is when you have to start using your imagination and envision “imaginary diamonds” in the appropriate spot, along with the corresponding imaginary lines.
Sound complicated? It is a little bit but like most things with pool and billiards, it just takes a bit of time and practice before it feels natural.
There are a wide range of methods for determining the diamonds on a table but many of them have one thing in common - you number them in a way that makes them easy to remember and calculate. The method below is one of the simpler methods and is good for getting started, but you can go a lot deeper and geekier if you wish!
Start at the foot rail. The corner pocket, where two cushions meet is 1. Go up the rail giving each diamond a number (1-5) and then do the same along the long rail and go up the rail giving each diamond a number (1-9). By doing this you will divide the table into 8 segments. A segment is the distance between 2 diamonds. Therefore the foot rail has 4 segments and the long rail has 8.
Diamonds that are unnumbered, are the ones between, for example, the 3 diamond and the 4 diamond so that would be 3.5. Remember, all that is really needed is to memorise parallel lines. The system works by assigning a number to the location of the cue ball and another number to the location of the object ball. To find out where to shoot the cue ball, all you have to do is subtract those two numbers.
All of this assumes no sidespin. If you stroke off center or are inconsistent you will get different results and it’s also important to know that there are many different diamond systems depending on how many rails you need to hit. It’s a personal thing that can vary from player to player.
The diamonds are an aid to banking. If you are attempting a bank shot, find the diamond that will make the object ball bounce off the rail and drop into the desired pocket. Remember that you need to aim the object ball into the correct diamond for a successful bank shot, and make sure the cue ball does not interfere with the path of the object ball after impact. The angle that the ball entered the rail is the angle that it left the rail - mirrored angles.
The two rails involved, the one you're shooting from and the one you're shooting to, are, as already mentioned, numbered.
If the cue ball is at the side pocket and the object ball is on the corner pocket but the path straight down the rail is blocked you may choose to bank to avoid the obstacle. Since the cue ball is at the side pocket and the side pocket is four diamonds from the corner using the divide by two method hit the opposite rail on the second diamond (half way between the corner and side pocket. By bouncing off the diamond that is 2 lengths from the pocket, the distance is cut in half, mirrored angles are created, and the ball travels the correct path to the pocket.
This is where things get a touch more complicated, but that is to be expected as we’re trying to get better at shots that are more complex. Like most elements of the diamond system, there are various methods for doing three rail kick shots, but the clearest one we found was the Corner-5 system from Dr Dave Billiards.
In the example above, the cue ball starting position is located over the corner pocket and using the system outlined by Dr Dave Billiards and the Corner-5 system, this means that the number of the starting position is five. If we aim up the table to the second diamond from the right on the bottom rail, this is aiming for diamond two. If we subtract two from five, we get three and with Dave’s system, we know that this means the cue ball will make contact with the opposite rail at diamond number three. Therefore, we can predict the path of a cue ball hitting multiple rails simply by doing a little bit of simple calculations.
One important thing to mention here is that just about every pool and billiards table will behave differently, so you should try to get a feel for the table and adjust your shots accordingly. Certain tables may mean that you need to use more or less English or more or less speed on the cue ball in order for the system to work accurately.
There are going to be times when you can’t aim for a diamond and have to aim slightly before or after the diamond in order to make your shot, This is why many diamond systems not only assign numbers to the diamonds themselves, but also to the halfway points between diamonds. Some systems will use whole numbers while others will use fractions such as 1.5, 2, 2.5 etc.
The cue ball has the same starting position for all five shots, but it’s only the first shot where the cue ball strikes the diamond exactly. The remaining four shots are all adjusted slightly to take into account the different positions of the balls.
The starting positions of the balls are slightly different so we can adjust the place where we aim for to make sure that we hit the target which in this case, is the top left pocket. It is also worth remembering that you can change you shot by altering the amount of English and speed that you put on the ball. Also remember as we said earlier, each table is different so you need to spend some time working out how it plays and adjust your shots accordingly.