Just in case you missed earlier articles, here is the pertinent Rule 5 a iii (Hardball Doubles Squash).

Allow either opponent to play the ball to any part of the front wall or back wall and to that part of each side wall in front of the red floor service line.

The “red floor service line” is properly named the “short line”.

Ball flight interference of shots that would go directly to the front wall are relatively easy to judge except when the opponent is near the boundary of the front wall triangle. The guidelines direct referees to assume a well positioned striker will be able to hit the front wall.

Ball flight interference of boasts are more difficult to judge. We can still assume a well positioned striker will be able to hit the side wall. However, all boasts to the side wall will not eventually reach the front wall fairly. It is therefore important as a player and as a referee to judge which intended boasts would reach the front wall fairly.

Players request a let because they believe an opponent would be hit by the ball. Referees have the job of judging the intended ball flight. They do this by imagining a line from the ball through the opponent and then onto either the front wall or a side wall. It is important to judge where the ball would have contacted a side wall. If the referee judges that the boast would not have reached the front wall fairly the let should be denied. If the intended boast is not an entitled shot, the let should be denied.

It is useful to have some strategies to judge which boasts will be good and which are doomed to failure.

Opponents are not required to clear for boasts directed to the back third of each side wall. This is what is inferred from Rule 5 a iii, however, many referees ignore that inference and grant lets when the boast is to the near wall.

What is the justification for Rule 5 suggesting that opponents need not clear for boasts directed to the back third of a side wall?

It is helpful to use some landmarks on the court. The short line is already acknowledged as an important landmark for serves and for clearing. The half line divides the back third into the two service courts.

Figure 610a shows the geometry from centre back wall to right side wall to left front corner. The sweet spot is where the short line meets the right side wall.

Shots from that test spot directed to any part of the back third of the side wall will fail. Good to know and why the rule states opponents do not have to clear that part of the side wall.

Figure 610b shows a realistic striking point just off the back wall.

From this point fair boasts must be ahead of the short line. In every case regardless of the striking point, there will be a front portion of the side wall that will produce fair boasts and a back portion of the side wall that will not produce fair boasts. The point on the side wall that is the boundary between the fair and not good boasts is the sweet spot.

Figure 610c shows a fair boast ahead of the sweet spot.

And not good boast deeper than the sweet spot.

Next time we will look at some other landmarks to use for judging boasts when a let is asked for.