Refer to the diagram above. For all cut shots, the direction the cue ball travels after contacting the object ball is always initially along the tangent line, which is 90 degrees to the shot line (the direction the object ball is being sent). This is useful knowledge that we can use to control the cue ball’s path from one shot to the next. And the rules are simple...
* If the cue ball slides into the object ball (a stun shot), it will slide along the tangent line and then continue to roll in the same direction as the tangent line until it stops rolling or hits something.
* If the cue ball rolls into the object ball, it will travel along the tangent line for a short distance before rolling across/beyond it as shown with the “Follow” path.
* If the cue ball is spinning backwards (a draw shot), it will travel the tangent line for a very short distance and then pull away from it at as shown with the “Draw” path.
It's important to understand that the harder/firmer you shoot the shot, the farther along the tangent line the cue ball will travel before any forward momentum kicks in or any draw/backspin kicks in.
You can learn more about using the tangent line in my newest book...
Playing to Win - How to Win More Often and Have More Fun Playing Pool
Click the button below to check out my "Position Play Fundamentals" video on the Poolology YouTube channel, which shows in detail how the tangent line applies to position play.