Once a flight path is known for a desired boast, that can be used to predict other boasts with the same result.
(Figure 607a)
See figure 607a. This is the same as figure 607 except the flight paths have been extended towards the back of the court.
Strike point #1 is a useful reference because of the court markings. The sweet spot for that shot is close to the middle of the side wall.
At least on paper, a shot from any point along flight path #1 that hits target “A” will reach the left front corner. Imagine sliding the ball (the blue dot) further and further back towards the back left corner. The target never changes. The angle never changes. The result, reaching the front left corner, never changes. Similarly sliding the ball along path #1 towards “A” and hitting target “A” will consistently produce the same results.
In a game, the ball strike is usually within a couple feet of the side wall. The ball at position #3 is about two feet out from the wall. You can check out #1 and #2 at about 2 feet from the side wall.
The focus has been on boasts reaching the far corner. That particular boast is important because what we have called the sweet spot divides the side wall into a front portion that produces fair boasts and a back portion that cannot produce a simple fair boast. Having a mental image of where the sweet spot is allows a range of boasts that will be fair and avoid attempting boasts that would come short of the front wall. A boast that arrives very close to the corner will often present a challenge to the opponents. But there are other boasts which may have less risk and be difficult for the opponents.
As with any shot, good players develop a feel for the shot. Whether it is a soft drop shot or a devastating serve, the player instinctively knows the targets and the weight needed. Practice, practice, and practice. There is no time to pull out a protractor and ruler on court.