Choose the natural path of the cue ball
The term "natural path" here means that when the cue ball is hit with centerball stroke (the natural stroke), the cue ball will then travel its natural path. You are probably wondering why this is important. The main reason why most good players choose the natural path of the cue ball whenever possible is because it is very easy to determine exactly where the cue ball will travel. You know that hitting the object ball (at an angle) with centerball stroke and medium speed on the cue ball will result in the cue ball to travel at a 90 degree angle from the direction of the object ball (refer to this lesson on basic position play). Playing the natural path is the only way for you to be absolutely sure where the cue ball will travel, where it will hit the rail, etc.
Hitting the cue ball above center or below center or with english presents you with a lot of different combinations of where to hit the cue ball. For example, hitting the cue ball with left english... you can hit the cue ball with 1/2 tip on the left of center or a full 1 tip off center. Now, these varying degrees of left english that you will put on the cue ball will generate different paths that the cue ball will travel after hitting the object ball therefore it is difficult to predict exactly where the cue ball will travel and how much angle it will create off the rail.
The sample illustration above shows you the natural path of the cue ball (indicated by the black dotted line) and the path that the cue ball might travel with left english applied on the cue ball (indicated by the white line) and also the probable cue ball path with the cue ball hit above center (indicated by gray line). You'll notice that with centerball stroke, you'll know exactly what path the cue ball travels... all you need to worry about is your speed control to position the cue ball exactly where you want it to be.
