Jack H. Koehler is the author of the best selling book The Science of Pocket Billiards. The experts have deemed that book the best book ever written on the subject of pocket billiards. His second book is Upscale One Pocket. Jack has graciously given us authorization to reprint a different excerpt from his book each month. Both books are available for purchase online at amazon.com.
	Bank Shots (part 2) By Jack Koehler, Single and multiple-rail bank shots are far more important in ONE-POCKET than in any other pool games (with the exception of BANK POOL). There are reasons why this is true: Your opponent is playing defense about half the time so you rarely get a good straight-in or cut shot. Therefore, you frequently have to shoot bank shots or get no offensive shots at all. In ONE-POCKET it is not necessary to make a ball for it to be a good shot. If it stops near your pocket, it is generally considered to be a successful offensive shot because your opponent must waste a shot trying to knock it away from your pocket. Therefore, even a low percentage bank, or multiple bank, becomes a good offensive shot. In other games, if you leave a ball hanging in the jaws of the pocket it's a disaster because your opponent will shoot it and score the point. In ONE-POCKET if the opponent shoots it into your pocket, it's a point for you. One of the most troublesome variables in shooting a bank shot is speed. In other pool games bank shots can, and sometimes must, be shot at speeds ranging from very slow to very fast. This causes all kinds of problems because the variation in speed causes the ball to come off the cushion at a different angle. Speed is not as much of a problem in ONE-POCKET because you generally want the ball to stop at the pocket if it is missed. Therefore, any given bank shot is almost always shot at the same speed (pocket speed) thereby eliminating one of the variables. Not having to adjust to the speed variable makes bank shots much easier to learn and execute. Bank-shot systems and techniques were thoroughly examined in THE SCIENCE OF POCKET BILLIARDS. However, since bank shots are the meat and potatoes of ONE-POCKET, a brief review of all banking systems is discussed here. For a more thorough expanation and analysis, the reader is referred to THE SCIENCE OF POCKET BILLIARDS. To successfully execute a bnank shot, the proper point on the cushion where the ball must strike and/or the direction it must be shot, must be determined. There are several techniques or systems that can be used to help determine one or both of these unknowns. Most of these systems actually determine the geometric banking point. The geometric banking point is the point on the rail track where the angle of incidence equals the angle of rebound. The geometric banking point must be corrected for ball speed, spin, rotation, etc. in order to determine the actual banking point. Before considering corrections, the various banking systems will be examined. They include the following: Equal angle system Equal distance system Crisscross system Rail track system Diamond system Image-table system Parallel system Rote system DIAMOND SYSTEM Few pocket billiard players are familiar with the diamond system. Many uninformed players think the diamond system is some sort of mystical pool panacea. Actually, the system was devised for the game of THREE-CUSHION BILLIARDS where points are scored only after three cushions and two balls are struck. Therefore, the system has somewhat limited application to the game of ONE-POCKET. For that reason, the diamond system will not be discussed here. For a complete analysis of the diamond system the reader is referred to THE SCIENCE OF POCKET BILLIARDS. IMAGE-TABLE SYSTEM With the image-table system another table is imagined adjacent to the real table, and the ball is aimed for the pocket on the imaginary table. An example of this system is shown in Figure 5-4. The ball is at point "A", the intended pocket is labeled "P", and the image pocket is "P'". Aim the ball as though it were being shot directly into image pocket "P'". The geometric banking point is where the aim line crosses the rail track (point "G"). Sounds simple but most people have trouble imagining the target pocket on the image table, in space, without visual references. If that is a problem for you try this: Stand near the image pocket "P'"; holding the cue stick vertically, place the butt on the floor directly below "P'"; sight through the stick back to the ball; point "G" is where the line of sight crosses the rail track of the real table. Remember where point "G" is, then go back and shoot the shot. Figure 5-4. Aim at the ball, or pocket, on the image table. If you have your own table (or are otherwise allowed), mark the floor at each image pocket. This will take the guesswork out of estimating where the image pocket is when using the vertical stick technique. This system also can be used for kick shots. The 5-ball in Figure 5-4 can't be shot directly into the pocket because of the intervening ball. To execute the kick shot, imagine that the 5-ball is in the exact same position on the image table, then shoot for the image 5-ball. The image-table system can be used for multiple rail bank shots as well. To determine where the pocket will be on a two rail shot simply hinge the image tables, using the cushion as a hinge, in the same order as the cushions are to be struck. Figure 5-5 show examples of how to find the proper direction to shoot ball "A" into pocket "P" for one-, two-, and three-rail shots. For the two-rail shot, cushion 1 will be struck first then cushion 2; hinge the table at cushion 1 first, now cushion 2 will be on top and must be hinged on that cushion next. Pocket "P" is now shown on the proper image table for the two-cushion bank. To shoot a three-rail shot, the image tables would have to be arranged as shown. Figure 5-5. The image-table system can be used for multiple-rail bank shots. The image-table system is superior to the previous systems because it primarily indicates the direction the ball must be shot; from this direction, the geometric banking point is determined. Most other banking systems are the opposite, they indicate the geometric banking point from which the proper direction can be determined. When the ball is on the cushion, the banking point is predetermined by virtue of its position; therefore, banking direction is the primary unknown. PARALLEL SYSTEM The parallel system is similar to the image-table system in that it primarily indicates the direction the ball must be shot rather than the banking point. This makes it applicable when the object ball is at, or very near, the banking cushion. The parallel system can be used for single rail or two-rail bank shots. Single Rail -- Figure 5-6 shows an example of a single-rail bank shot using this system. The objective is to bank ball "A" into the corner pocket "P". Find the midpoint (point "M") directly between ball "A" and pocket "P". Imagine a line from point "M" to the opposite pocket "N". Imagine another line parallel to line "MN" from "A" to the banking cushion. The point where this line crosses the rail track (point "G") is the geometric banking point. The line "AG" may be easier to visualize if the cue stick is held over the midpoint "M" with the tip pointing at pocket "N". Figure 5-6. The single-rail parallel system. Estimating the line "AG" is difficult when the ball is a great distance from the pocket even when the cue stick is used as an aid. In these cases a variation of this system can be employed. This variation is shown in Figure 5-7. Find the midpoint "M"; use the cue stick, as shown, to define line "MN"; observe where the butt of the stick crosses the rail track of the near cushion. This point will be called the complimentary banking point. The geometric banking point is this exact point on the rail track of the opposite cushion. In Figure 5-7, the complimentary banking point is on the rail track 2 inches from a diamond. The geometric banking point is 2 inches from the corresponding diamond on the rail track of the opposite side rail. Figure 5-7. The parallel system using the complimentary banking point. The parallel system is also effective in determining the geometric banking point for kick shots. Figure 5-8 shows an example of a kick shot at ball "A". Imagine a point on the rail track of the banking cushion perpendicular to ball "A" (point "B"); find the midpoint "M" between the cue ball and the ball "A"; imagine a line from point "M" to boint "B"; shoot into the cushion parallel to line "MB". The same system can be used in kicking to the end rail at ball "A". Using the same midpoint "M", imagine point "D" on the rail track of the end rail perpendicular to ball "A"; shoot into the end rail parallel to line "MD". Two Rails -- The parallel system can also be used for two-rail bank shots. As shown in Figure 5-9, the two-rail bank shot is similar to the one-rail shot except that a different pocket is used for parallel alignment. First, find the midpoint "M" between ball "A" and the intended pocket "P"; draw a line through the midpoint to the corner pocket where the two banking rails meet (pocket "E"); shoot into the rail parallel to line "ME". Note that the path of ball "A" is an equal distance (distance "x") from the midpoint line both going to the first cushion and coming off the second cushion. This makes the system easy to use when shooting a kick shot. Figure 5-8. The parallel system used for kick shots. Figure 5-9. The parallel system used for a two-rail bank shot. Figure 5-10 shows how the two-rail parallel system can be used to kick into another ball. Find the midpoint "M" between the cue ball and the ball to be kicked (3-ball). Draw line "ME" from the midpoint to the corner pocket where the banking rails meet; shoot into the rail parallel to line "ME". Note: The midpoint line can be drawn to any of the four corner pockets allowing several options for the two-rail kick shot. Figure 5-10. The parallel system used for a two-rail kick shots Although the two-rail parallel system is geometrically correct, in reality, the ball comes off the second rail moving away from the midpoint line. This error is caused by cushion distortion and cushion-induced english. For kick shots, a correction for the error can sometimes be made by using top running english. The slower the shot and/or the smaller the angle of incidence, the less english is required. When this system is used to shoot an object ball two rails, english can't be used to correct for the variables; in these cases, the error must be anticipated and the banking point moved closer to the pocket at the end of the midpoint line. ROTE SYSTEM All the previously discussed banking systems help to determine the geometric banking point and/or the direction the ball must be shot. After executing a particular bank shot many times it is no longer necessary to divide angles, imagine lines, points, etc. For example, in practicing a particular bank shot; one of the systems can be used to determine the banking point. After shooting the same shot several times it will not be necessary to go throught he same analysis each time--it will be remembered from the previous analysis. This is essentially what the rote system is; a bank shot is repeated many times so that the proper banking point is committed to memory. Most professional pool players use the rote system. Any player that plays long enough and often enough will build up a memory bank of bank shots, most ONE-POCKET players fit into this category. This means less and less analysis will be required. This system is learned by constant practice, the only way it can be maintained is by repeatedly refreshing the memory with more practice. The biggest problem with this system is that it can't be passed on to another player. The greatest players in the world can pass on their knowledge but not their memories.   All copyrights are owned by Jack Koehler. No duplication is allowed without his permission.