(Figure 610j)

See Figure 610j. The diagonal shown divides the service court into two halves.
The concern is, when will boasts be successful and when are they doomed to failure. And the focus is when are boasts possible when the back third of the side wall is utilized. It was shown in the previous article (Figure 610i) that there are no viable cross court boasts from the service court to the far back third of the side wall.
There is good reason for dividing the service court into these two halves. It will be shown that fair boasts to the near back third are not possible when the striking point is within the front triangle (the coloured section). Fair boasts are possible from the back triangle.
Be reminded that opponents are required to allow strikers to play boasts to any part of the front 2/3 of either side wall. And by inference, opponents are not required to clear for boasts to any part of the back 1/3. It is reasonable to assume that the striker is not entitled to boasts that would not reach the front wall fairly. An opponent in the way of a shot that would not reach the front wall fairly is not guilty of ball flight interference.
(Figure 610k)

See Figure 610k.
The sweet spot is at the short line for a shot taken from position #1. Fair boasts are possible along the side wall ahead of the short line. Fair boasts are not possible along the back third of the side wall.
(Figure 610L)

See Figure 610L. If the striking point is anywhere along the diagonal such as #2 or #3, the sweet spot remains the same.
If the striking point is anywhere in the front triangle (green coloured portion) the sweet spot will be somewhere ahead of the short line. There are no fair boasts opportunities from that triangle to the back third of the side wall.
To summarize so far, there are two reasons why a let should be denied when the opponent is along the back third of the side wall and the strike point is somewhere in the left service court or the front triangle of the right service court. One, boasts would not reach the front wall fairly. Two, the striker is not entitled to boasts to the back third of the court.
It is recognized that the safe area for opponents is generally the side wall behind the short line. The safe area extends beyond just along the wall. The opponent is safe anywhere in the back half of the service court if the strike point is in the coloured areas.
Now the controversy begins. Next up, boasts originating from the back half of the service court.