CiSRA Puzzle Competition 2009 - Solutions

This is the archive of the 2009 Puzzle Competition. Please visit the current competition site for information about the latest Puzzle Competition.

A.2 Meet Your Match

Each diagram is a side-on representation of the trajectory of the ball when playing a particular sport. Specifically, each diagram represents a certain scoring situation in its respective sport.

Top row, left: Volleyball
The trajectory involves throwing the ball up and serving it, and the receiving team performing a "dig", "set", and "spike" series of hits. The serving team is then unable to return the ball (it bounces within the court and then proceeds out of the court). This diagram represents the receiving team getting a score of 1 point. (It used to be 0, but modern volleyball rules award the receiving team a point for winning a rally.)

Top row, right: Golf
The trajectory involves a drive, an approach shot which lands in front of the putting green, a pitch to the back of the putting green (which is slightly elevated, as is common on golf courses), a first putt past the hole, and a second putt into the hole. The total score is 5.

Middle, row, left: Basketball
The trajectory involves a number of passes of the ball between the players, and some sequences where players dribbled the ball by bouncing along the ground while walking. A shot is taken at the basket, and the ball characteristically bounces against the backboard and circles the hoop before dropping through the basket. By carefully measuring the height of the hoop above the ground, we can be sure that the basket was shot from a position well beyond the 3-point line, so this diagram shows a player making a score of 3.

Middle row, right: Soccer
The trajectory involves a complex sequence of repeated passes along the ground and through shallow arcs above the ground, followed by an attempt at scoring a goal that sees the ball bounce off the top rail of the goal (or the goalkeeper's hands). Hence, 0 points are scored.

Bottom row, left: Cricket
The trajectory shows the bowler running with the ball in hand followed by the characteristic over-arm bowling motion. After bouncing once, the ball is hit by the batting player into the field where it runs along the ground for a distance. At the end of its path, the ball hits the boundary rope of the oval, kicking up into the air slightly. Hence a score of 4 runs is achieved by this series of events.

Borrom row, right: Ten-pin bowling
The trajectory shows the player walking towards the foul line, sweeping the ball back and bowling it forward along the ground. At the end of the lane, the ball is collected by the automatic retrieval mechanism, where it is raised by a conveyor and returned via a tunnel underneath the surface of the lane. Finally, the ball is raised into the ball return area behind the bowler by an additional conveyor mechanism. Notice that during the part where the ball travels along the surface of the lane, it falls a short distance vertically. This is a gutter ball, which doesn't strike any pins, and hence scores 0.

By filling in the scores onto the chart, the number series 15, 30, 40 is assembled. These numbers are part of the distinctive scoring pattern used in tennis. The empty space at the top of the puzzle suggests that we need to find something that comes before this number sequence - in tennis, the zero score is LOVE, providing the final answer (and hopefuly what happens when you meet your match).