I will explain an aiming system (shaft) that I saw in a video of Shane Van Boening teaching. I went to the poolhall the next day and spent 2 1/2 hours working on the details of it.
3 basic shots
1) straight in (or close to) = straight to 15 degrees outside of straight
2) Cut shot = 15 degrees up to 60 degrees (most shots in pool)
3) very thin cut shot = 60 degrees to 90 degrees
Before I explain the 3, you need to know how to find the contact point. For straight in shots it is drawing a line from the center of the pocket through the center of the object ball and where that line comes out the object ball is the contact point. I stress straight in shots because once you add angle of a cut (or apply english) you need to adjust this for contact throw. The adjustment is to over-cut the ball. So instead of using the center of the pocket, start to the short side of the pocket and then find the contact point.
2nd important bit of information. All of this is based on shooting through the center of the cueball.
1) Straight in shots - Find the contact point and simply aim the center of your tip for the contact point.
2) Cut shots - Cutting the ball to the left (15 degrees to 60 degrees) you find the contact point and aim the left side of your cue stick for the contact point. The center of your cue should still be lined up through the center of the cue ball (as in all these). If you are cutting to the right you aim the right side of your stick for the contact point.
3) Very thin cuts - 60 degree's or so - cutting to the left you line up the left side of your cue about 1/8th of an inch outside of the object ball (yes you aim away from the ball slightly). Thin cuts is the only shots that i find this is not concrete because the closer you get to 90 degrees you aim closer to 1/2 an inch away from the ball.
Remember, this is for center ball hits without english and adjuststing your contact point to slightly over cut your cut shots. When applying english you have 2 adjustments. 1 is to ajust the contact point based off of what english/speed to adjust for contact throw. 2 is that you will use the 3 aiming rules above to find the line of the shot (still from the center of the cue ball) and then parallel your cue to the desired english. And this adjustment is all based on a low deflection shaft.
A good drill for testing this is to place 5 balls from the foot rail, spaced 1 ball off the rail for the first ball, then 1 ball space between each ball (going up to near the footspot). Then place the cue ball 1/2 diamond in front of the side pocket (for all shots the cue ball will be placed back to this spot). SHoot the first ball into the corner, should be a very slight cut. Repeat 5 to 10 times. Then shoot the 2nd ball to the corner, should be slightly more of a cut, repeat. Then pregress to the 3rd ball (medium cut), then the 4th ball (thin cut) then the 5th ball (very thin cut). Try to master all 5 with the aiming system with center ball hit. Then go back through and try using varying degrees of english for each shot.
