Bank Shots: Mastering the Geometry and Physics in Pool
Bank shots are a crucial aspect of pool, where the rail is utilized to pocket an object ball. Whether it’s striking the object ball to a cushion first or using the cushion before hitting the object ball, executing bank shots can significantly increase your chances of winning.
Understanding the geometry of bank shots is relatively straightforward, but the physics involved introduces numerous variables that impact the shot’s outcome. Factors such as ball spin, slide, friction, and the depth of ball sinking into the rail all influence the success of a bank shot.
When shooting a center cue ball for a bank shot, one might assume that the return angle would match the angle at which the ball approached the rail. However, that’s not the case. The forward roll of the ball causes it to move slightly forward from the geometric line. Conversely, when the same shot is executed with more force, the ball follows closer to the geometric line. The absence of rolling before contacting the rail keeps the ball on a trajectory closer to the intended path.
The transfer of English (sidespin) from the cue ball to the object ball can have a significant impact on bank shots. Despite previous beliefs that this was not possible, applying sidespin can enable you to make seemingly impossible bank shots. It requires adjusting the contact point on the object ball due to the natural throw caused by sidespin. Additionally, a relatively soft shot is necessary to allow the sidespin to take effect off the rail.
When banking an object ball close to the rail, it’s important to consider that the object ball will be sliding upon contact with the rail. Consequently, it may appear to fall short on the return angle after contacting the rail. To execute this shot correctly, one must strike the object ball thinner to compensate for this effect. Some shots may also require outside English or throw to achieve the desired return angle.
At times, when we strike an object ball, it seems to travel straighter than anticipated based on the point of contact. This occurs due to the friction between the two balls, causing the object ball to momentarily follow the direction the cue ball was traveling. Many beginner players make this common mistake, which can be rectified by applying a small amount of outside English. This is particularly true for bank shots where the object ball is within approximately 6 inches of the rail.
Bank shots that involve sending the cue ball to a rail before contacting an object ball are often referred to as lag shots. These shots are highly valuable when you don’t have a clear line of sight on the object ball, especially when recovering from your opponent’s safety play. In many ways, the geometric line of these shots is more predictable, as you can adjust the cue ball’s spin and speed to achieve the desired return angle after the rail contact. Diagrams illustrating impressive results that can be attained with a simple lag shot further emphasize its effectiveness.
In certain situations, lag shots are a superior choice compared to hitting the object ball first. When a ball obstructs a pocket, opting to hit a rail first before pocketing the ball can provide greater positional play options. Examples showcasing this strategy are depicted, highlighting how a lag shot can be the preferred approach to achieve the desired position for your subsequent shot.
