When is the rule the law? A few conditions have to be met for a referee to award a let or point for ball flight interference.

• Timing is critical but not easy.
• The let should be requested the instant before the ball would have been struck.
• The striker should be in position to make the desired shot.
• The shot should be an entitled shot.
• The shot would otherwise have made it to the front wall fairly.

I think the following paragraph needs splitting up or some such.
What can go wrong? Sometimes the striker misjudges the situation and requests a let well before the ball is within striking distance. It is an easy mistake to make. The striker sees an opponent in the way of a shot they anticipate making but the ball is not yet there to hit. Other times the striker leaves it too late to request the let. The striker is no longer in a good position to strike the ball. A player may not be in an ideal position and leaves the ball hoping to get back for a better shot. Be careful, a let is granted for the situation at the moment the let is requested, not for some prior situation. Ball flight interference demands that the striker is ready, and the ball is in position to be struck at the moment the let is requested. There may be other types of interference occurring but must be treated as such.

If the striker’s body position is awkward or is they are reaching back to reach retrieve the ball, it may be judged that the striker is looking for a let to get out of a poor situation.

added bold highlighting
If a shot is not entitled, there should be no let. However, this is when the rule is sometimes not followed.

Some shots are definitely desperate attempts and have no hope of reaching the front wall fairly. Like other parts of the rules there are guidelines to help make good judgements and keep the job of the referee manageable. For example, it is made clear that the referee should assume that a ready player will be able to hit the ball directly to the front wall. The fact that the player had put three backhands into the tin should not influence the decision. Boasts are a bit more complicated. The referee should not be saddled with complaints that a three wall would have made it or the boast with side spin would have made it. The referee should be responsible for judging a simple boast, side wall and then onto the front wall.

We will now have a look at some boasts to the back third of the side wall. These are not entitled boasts but referees frequently award lets. This is an issue which should be specifically resolved within the rules. Either modify the rule or add a guideline instructing referees to abide by the rule and not award a let for these unentitled boasts.

Fair boasts are possible from the back triangle. However, Rule 5 iii infers that the entitled portion of the right wall ends at the short line. The opponent is shown in two positions, A and B.

If the striker requests a let when Yellow is at position “A” there is no let. The boast through yellow would not be fair. In addition, Yellow has cleared to the side wall which is not entitled to the striker.

If Yellow is at position “B”, a boast through Yellow would be fair. If Rule 5 is to be followed, the referee has to judge if the boast would have touched the side wall in front of the short line or behind the short line. In live action this would be difficult to judge. On paper the ball would hit the side wall behind the short line. That is not an entitled shot, therefore no let. Is Yellow interfering with a boast that would touch the side wall ahead of the short line.? Again, on paper no. No let. In a match it would not be outrageous for the referee to judge it is interference.

The striker position has moved further up the court but still inside the back triangle. Now it is pretty clear that Yellow at position A, is interfering with a fair boast. The boast would contact the side wall a little behind the service box. It is also clear that Yellow at position A has cleared to the side wall and is not interfering with an entitled shot. Yellow at A is not interfering with fair boasts directed ahead of the short line. In this case a referee allowing a let is effectively contravening Rule 5. The boast is only possible if the ball contacts the side wall behind the short line which is not an entitled shot. It is certainly a possible and fair shot, but not entitled.

Yellow at B is interfering with a fair boast that would contact the side wall ahead of the short line. That is interference. A let should be awarded.

There are various views about what constitutes a let for a boast directed to the back third right side from a position somewhere in the back third of the court.

What should be clear and consistent is a boast originating from the left back court is never a let if the opponent is anywhere in the back triangle.

In addition, a boast originating from the front triangle is never a let if the opponent is anywhere in the back triangle. This is not about entitled or not entitled, it is about the boast not reaching the front wall fairly. The same reasoning certainly applies to the mirror image for the left side. Conflicting views arise because the division of entitled and unentitled set out in Rule 5 is not universally respected.