There is of course the famous Bermuda triangle but doubles squash also has a famous triangle.

Three points define any triangle.

The front wall triangle has two fixed points, the left front corner, and the right front corner. The missing point is the striking point of the ball. Another way to imagine the front wall triangle is the front wall is the base of the triangle and the apex is the striking point of the ball. The base is always the same. The shape of the triangle is determined by the ball position.

This is an important image as it relates to ball flight interference. It is so famous it is often just referred to as THE triangle; perhaps better named as the front wall triangle. We keep going back to Rule 5 a iii.

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.

Notice the phrase, “to any part of the front wall”. This part of Rule 5 is brought into the discussion because it is easier to understand compared to the boast.

By the way, THE triangle is never mentioned in the rules; but it is mentioned in supplementary documents.

See figures 612a, b and c. All the above figures show the base as the front wall. The ball is always the apex. The importance of the triangle is that it defines a no go zone for the opponents of the striker. If a let is requested, the referee judges where the ball was at the instant the let was requested. Then they visualize the triangle defined by the ball position. If the referee judges that the opponent was in the no go zone, then a shot was prevented that could have travelled directly to the front wall. That is flight interference.

If no let is requested but the ball is struck and an opponent is hit by the ball, then the referee must decide if the opponent was in the no go zone. The opponents must allow the striker to play the ball to any part of the front wall. Wow, that is a lot of space. It is assumed that the striker is in position to strike the ball directly to the front wall. The opponents must be out of the front wall triangle.

The shape of the triangle changes as the striking point shifts from #1 to #2 to #3.

Looking at the three triangles it is clear that the opponents moving to a side wall is a good idea in order to avoid being caught in the no go zone. Being deeper in the court than the ball is also a safe place. It is simple, for a boast or direct front wall shot, the ball must go forward. Yes, the ball can also be played onto the back wall.