Zone 1
The Plus System is divided into five different zones. Each zone has its rules which must be obeyed.
Zone 1: Start Rail between 20 and 60
The Calculation Formula
3rd RAIL - START RAIL = 1st RAIL
The single steps to calculate a rail-first shot to the third rail by inserting it into the formula:
Estimate the arrival value on the third rail.
Select a possible point on the start rail and enter it into the formula.
The formula brings the result for the value on the first rail. Now, using the cue, you imagine a line which connects the selected point on the start rail with the value on the first rail. If you realize that the point on the start rail which you selected in step 2 produces a line, which is clearly further than 5cm away from the cue ball, you must select a point on the start rail which is more suitable and enter this one into the formula.
If the cue ball is slightly beside this line, it can be shifted parallel until it crosses exactly the center of the cue ball. The point where this line reaches the first rail, is your aiming point.
Prerequisites of the Stroke
In most zones the Plus System is played with a little bit of running English. In order to determine the right amount of English, I suggest to play the reference line from 30 to 30 and to try out the amount of English, which causes the cue ball to arrive at 60 on the third rail. Normally, this is about one cue tip of English.
Video
Example
Instructions
Determine the point of arrival on the third rail (at first by estimation). We receive a value of 55.
Choose a possible start value and insert it into the formula. 3rd rail 55 - start rail 30 = 1st rail 25.
The result of the calculation is the value on the first rail. Now imagine a line from the chosen start value (30) to the value on the first rail (25). If you realize, that this line is far away from the cue ball, you try another start value and insert it into the formula.
If the line is close to the cue ball (less than 5 cm), you just shift it parallel, till you cross exactly the center of the cue ball. The point where this line reaches the first rail is your aiming point.
