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Right on target

By David, 27 May 2014 Activity

You will need

Soemoen drawing on the ground with chalk. They are measuring distances with a tape measure.

Draw each circle 15 cm from the last one.

  • Large concrete area
  • Chalk
  • Hacky-sack or small bean bag for throwing
  • Some friends to play with
  • Tape measure (optional)

To make the field

  1. Draw five circles, one inside the other, on the concrete with chalk. They should all have the same centre point, and their diameters (widths) should be 30 cm, 60 cm, 90 cm, 120 cm and 150 cm.

    five concentric circles - the outside one is numbered 1, and the numbers increase as they go  in.

    Number the circles starting with the outside one and moving inwards.

  2. Number the circles, with the largest circle numbered 1, the next largest 2, and so on. The smallest circle is numbered 5.

How to play

  1. This game has several rounds, and each player has a go being first in a round.
  2. Each round, the first player chooses a special way to throw the hacky sack (say over the head, or after spinning on the spot) and a place to throw from.
  3. Starting with the first player, every player attempts to throw the hacky-sack onto the target in the special way.
  4. Before the throw, each player must choose the target they are aiming for. They call out a number from 1-5.

    A ball is in the third concentric circle.

    This throw is inside the 3, 2 and 1 circles.

  5. If the hacky-sack lands inside the circle they called out, or a smaller circle, they made the shot! That player gets the points for the circle they called out (not the one the hack-sack landed in). If the hacky-sack landed outside the circle they called out, they score no points.
  6. Once everyone has had a go at choosing the shot, players add up their points. The player with the highest score wins!

What’s happening?

This activity is all about estimating errors. If the players could always get the hacky-sack to hit the middle of the target, the game wouldn’t be any fun. If you make the throws hard enough, people won’t always hit the middle of the target and guessing the right circle becomes very important.

A man throwing a ball while standing on one leg and covering his eyes.

Try throwing while standing on one leg, or with your eyes closed.

If you choose the ‘1’ circle all the time, you’ll get points on more rounds, but you’ll only get one point each time you succeed. If you pick the ‘5’ all the time, then you probably won’t get points very often, but when you do, it will be lots of points.

A good strategy is to match your prediction with how easy you think the shot is. If you think the shot is easy, then choose a high value target. You’ve got a good chance at getting lots of points. If you think the shot is hard, then choose a big target. That way you’ve got a better chance of getting at least something.

Applications

In many sports, players have to make the choice between making an easy shot for fewer points, or trying for a harder shot worth more. For example, in rugby league, a penalty can be taken as a kick for goal worth two points, or the team can tap the ball and go for a try worth four or even six points.

A team that is behind may be more likely to try for risky shots worth more points. On the other hand, if a team only needs a few points to secure their lead, they may choose to take low scoring, safe shots. Both of these actions have more pronounced effects at the end of the game, where there won’t be many more opportunities to change the final result.

Being good at throwing is very important in this game. If you want a game where guessing is more important than throwing, you could try this variant:

  1. Before each player makes their throw, every other person writes down which circle they think the hacky-sack will end up in.
  2. The throwing player doesn’t make a prediction.
  3. The thrower scores points for the smallest circle they hit.
  4. Everyone else scores points if their guess was right.

You could also try exchanging the hacky-sack for Velcro darts or any other game that uses a bull’s-eye target.

More information

An interesting puzzle about archery

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